1 00:00:05,800 --> 00:00:07,680 Speaker 1: Hey, you welcome to Stuff to Blow your Mind. My 2 00:00:07,760 --> 00:00:10,719 Speaker 1: name is Robert Lamb and I'm Joe McCormick, and it's Saturday. 3 00:00:10,720 --> 00:00:13,640 Speaker 1: Time to go into the vault. We may get eaten alive. Well, 4 00:00:13,840 --> 00:00:16,240 Speaker 1: I think we're gonna be safe because it certainly this 5 00:00:16,280 --> 00:00:18,840 Speaker 1: episode is about sex cannibals. So the vault does contain 6 00:00:18,920 --> 00:00:23,120 Speaker 1: sex cannibals. However, they're not human. They're not human sex cannibals, 7 00:00:23,160 --> 00:00:27,560 Speaker 1: So you're not going to encounter, you know, any grotesque 8 00:00:27,600 --> 00:00:32,159 Speaker 1: tales of humanoid sex cannibals in this episode. Right, But 9 00:00:32,240 --> 00:00:35,720 Speaker 1: if we were like bachelor spiders, be a whole other story. Yeah, 10 00:00:35,760 --> 00:00:39,000 Speaker 1: if you were a spider listening to this podcast, then 11 00:00:39,400 --> 00:00:42,640 Speaker 1: you know, I would say, you know, proceed with caution. 12 00:00:43,040 --> 00:00:44,760 Speaker 1: This one was a lot of fun. We hope you 13 00:00:44,880 --> 00:00:49,400 Speaker 1: enjoy it too. It originally aired Thursday, March tenth. Uh 14 00:00:49,440 --> 00:00:52,120 Speaker 1: So i'd say, without any further ado, let's throw you 15 00:00:52,240 --> 00:00:59,080 Speaker 1: right into the sex cannibals. Welcome to Stuff to Blow 16 00:00:59,120 --> 00:01:10,120 Speaker 1: your Mind from stuff where its dot com. Hey what 17 00:01:10,240 --> 00:01:11,680 Speaker 1: can this stuff to blow your mind? My name is 18 00:01:11,760 --> 00:01:13,920 Speaker 1: Robert lamp and my name is Joe McCormick, and we're 19 00:01:13,920 --> 00:01:16,240 Speaker 1: gonna get right to it today because we're going to 20 00:01:16,319 --> 00:01:18,959 Speaker 1: talk about sexual cannibalism, right And I do want to 21 00:01:18,959 --> 00:01:21,400 Speaker 1: just throw out here right at the top, this is 22 00:01:21,440 --> 00:01:24,120 Speaker 1: not going to concern human cannibalism at all. I know 23 00:01:24,200 --> 00:01:28,839 Speaker 1: that in the past when we've covered cannibalistic topics, some 24 00:01:29,160 --> 00:01:31,640 Speaker 1: listeners have actually skipped the episode thinking that there might 25 00:01:31,680 --> 00:01:33,920 Speaker 1: be human cannibals in it. I'm just gonna let you know, 26 00:01:34,080 --> 00:01:37,240 Speaker 1: if you've made it this far, no human cannibals will 27 00:01:37,760 --> 00:01:40,399 Speaker 1: cannibals will occur in this episode. Is that some people's 28 00:01:40,440 --> 00:01:42,959 Speaker 1: big thing. It's like, Oh, you're gonna talk about cannibalism. 29 00:01:43,040 --> 00:01:45,480 Speaker 1: I can't go on. Well, you know, I mean some listeners, 30 00:01:45,600 --> 00:01:48,480 Speaker 1: some of our listeners really want the dark content, and 31 00:01:48,520 --> 00:01:51,000 Speaker 1: that's why and and and we're certainly happy to go 32 00:01:51,080 --> 00:01:54,360 Speaker 1: there and as well as strip away some of the uh, 33 00:01:54,680 --> 00:01:58,880 Speaker 1: the the taboo and the mystery surrounding those dark topics. 34 00:01:59,600 --> 00:02:02,600 Speaker 1: But I know that not everyone wants to go down 35 00:02:02,600 --> 00:02:04,160 Speaker 1: that path with us. So I just want to let 36 00:02:04,160 --> 00:02:08,200 Speaker 1: everyone know we're not going down the human cannibal path. Okay, 37 00:02:08,240 --> 00:02:11,200 Speaker 1: So we are going to be talking about animal sexual cannibalism, 38 00:02:11,240 --> 00:02:13,320 Speaker 1: and this is a topic that's been touched on on 39 00:02:13,360 --> 00:02:15,440 Speaker 1: the show before I Know You and Julie in the 40 00:02:15,440 --> 00:02:19,440 Speaker 1: past did an episode about cannibalism in the animal world, 41 00:02:20,280 --> 00:02:23,800 Speaker 1: but today we wanted to focus specifically on sexual cannibalism 42 00:02:23,800 --> 00:02:28,400 Speaker 1: because of all of the interesting evolutionary interplay here, the 43 00:02:28,480 --> 00:02:31,200 Speaker 1: sort of trade off of costs and benefits that would 44 00:02:31,280 --> 00:02:36,119 Speaker 1: lead a species to at some rate fairly often enough 45 00:02:36,200 --> 00:02:39,680 Speaker 1: that people would notice eat during sex, eat each other 46 00:02:39,800 --> 00:02:42,960 Speaker 1: during sex or after sex. Yeah, And it's the interesting 47 00:02:42,960 --> 00:02:45,360 Speaker 1: thing about this topic is that, on one hand, it 48 00:02:45,400 --> 00:02:47,960 Speaker 1: is very simplistic, and I'll get into the simplistic argument shortly, 49 00:02:48,160 --> 00:02:50,359 Speaker 1: but then it's also not as cut and drives. You 50 00:02:50,440 --> 00:02:53,880 Speaker 1: might think. It's scenario where they are multiple theories as 51 00:02:53,919 --> 00:02:57,000 Speaker 1: to as to how this evolved and exactly how it's working, 52 00:02:57,160 --> 00:02:59,880 Speaker 1: and some of those are actually conflicting theories as well. 53 00:03:00,440 --> 00:03:02,440 Speaker 1: So it's, uh, it's a subject with a lot of 54 00:03:02,480 --> 00:03:06,079 Speaker 1: meat on it, a lot of sexy meat on it. Okay, 55 00:03:06,120 --> 00:03:09,960 Speaker 1: So what's the basic gist of why sexual cannibalism happens. 56 00:03:09,960 --> 00:03:12,359 Speaker 1: This might be kind of obvious, but we should get 57 00:03:12,360 --> 00:03:13,919 Speaker 1: it on the table so that we have a place 58 00:03:13,960 --> 00:03:17,360 Speaker 1: to start. So let's say you have two spiders, and 59 00:03:17,760 --> 00:03:20,839 Speaker 1: they size each other up, and they say it's time 60 00:03:20,880 --> 00:03:23,520 Speaker 1: to mate, you know, we'll pass our genes on. But 61 00:03:23,960 --> 00:03:27,200 Speaker 1: some way through the mating procedure, the female sort of 62 00:03:27,360 --> 00:03:30,840 Speaker 1: grabs hold of the mail and sinks her fangs into 63 00:03:30,919 --> 00:03:34,800 Speaker 1: him and drains all of his delicious juices? Why did 64 00:03:34,840 --> 00:03:39,800 Speaker 1: that happen? And that's and that is the big question, right, 65 00:03:39,800 --> 00:03:43,120 Speaker 1: why does this evolve? And why does this occur? Certainly 66 00:03:43,200 --> 00:03:46,320 Speaker 1: not in every species, it's actually a very rare occurrence 67 00:03:46,800 --> 00:03:50,880 Speaker 1: in the natural world. But where it does occur, uh, 68 00:03:50,920 --> 00:03:53,160 Speaker 1: we can't help but study it well. Actually we should 69 00:03:53,160 --> 00:03:56,040 Speaker 1: start with the simple side. It's clear why this happens 70 00:03:56,280 --> 00:03:58,400 Speaker 1: from the female side. A lot of the question is 71 00:03:58,440 --> 00:04:01,280 Speaker 1: why the male would participate it in this right, But 72 00:04:01,280 --> 00:04:04,480 Speaker 1: but why does the female eat the male? Well? For energy? 73 00:04:04,520 --> 00:04:07,200 Speaker 1: Of course? I mean that. I mean that basically comes 74 00:04:07,200 --> 00:04:12,240 Speaker 1: down to stripping away the human complexity surrounding cannibalism in general, 75 00:04:12,320 --> 00:04:17,480 Speaker 1: because ultimately, flesh is energy, flesh is food, uh, flesh 76 00:04:17,560 --> 00:04:20,240 Speaker 1: is life. In addition, and so in addition to having 77 00:04:20,240 --> 00:04:23,440 Speaker 1: all sorts of cultural hangups about cannibalism, you know, we 78 00:04:23,480 --> 00:04:27,120 Speaker 1: don't have any problem wasting boatloads of food and energy, right, 79 00:04:27,480 --> 00:04:29,360 Speaker 1: So we kind of have to put that aside to 80 00:04:29,400 --> 00:04:31,599 Speaker 1: think of it. But yeah, in the in the natural world, 81 00:04:31,680 --> 00:04:34,600 Speaker 1: you see plenty of cases of just straight up cannibalism, 82 00:04:34,640 --> 00:04:37,640 Speaker 1: and it all comes down to a basic economy of 83 00:04:37,680 --> 00:04:42,359 Speaker 1: the energy. So a mother's young die, she might consume 84 00:04:42,400 --> 00:04:47,160 Speaker 1: those young because what are they now but empty vessels 85 00:04:47,720 --> 00:04:50,640 Speaker 1: made up of energy. Yeah, I think this is something 86 00:04:50,680 --> 00:04:53,919 Speaker 1: that's hard for us to understand because, by and large, 87 00:04:53,960 --> 00:04:56,919 Speaker 1: if you are a human being listening to a podcast, 88 00:04:56,960 --> 00:04:59,960 Speaker 1: you probably are are lucky. You live a fortunate exist 89 00:05:00,040 --> 00:05:02,760 Speaker 1: stence where you have decent amounts of access to food. 90 00:05:02,800 --> 00:05:06,440 Speaker 1: You're you're probably not living constantly at the edge of starvation, 91 00:05:07,200 --> 00:05:11,680 Speaker 1: and animals are sort of built with the assumption that 92 00:05:11,800 --> 00:05:14,960 Speaker 1: they will be living constantly at the edge of starvation. 93 00:05:15,200 --> 00:05:16,760 Speaker 1: If you ever you ever noticed how if you have 94 00:05:16,800 --> 00:05:20,680 Speaker 1: a dog at home, if you're out walking the dog 95 00:05:21,000 --> 00:05:25,279 Speaker 1: and there's something that smells even remotely like it might 96 00:05:25,400 --> 00:05:27,160 Speaker 1: be food, the dog's going to try to put it 97 00:05:27,160 --> 00:05:29,320 Speaker 1: in better, go ahead and get in the mouth anyway, 98 00:05:29,400 --> 00:05:31,479 Speaker 1: see what it takes. And you and I would never 99 00:05:31,600 --> 00:05:34,560 Speaker 1: think that way. I mean, it's like smells like it 100 00:05:34,640 --> 00:05:36,960 Speaker 1: could be food. Who knows if it would hurt me. 101 00:05:37,080 --> 00:05:40,320 Speaker 1: Better safe than sorry, I'm just gonna eat it. Um. 102 00:05:40,360 --> 00:05:42,960 Speaker 1: But in the animal kingdom, out in the wild, that 103 00:05:43,080 --> 00:05:45,840 Speaker 1: sort of strategy might make a lot more sense because 104 00:05:45,920 --> 00:05:48,960 Speaker 1: if you are constantly at risk of having your life 105 00:05:49,000 --> 00:05:53,000 Speaker 1: extinguished or your competitive power diminished by lack of access 106 00:05:53,040 --> 00:05:57,120 Speaker 1: to energy resources, you'll take anything you can get. Yeah, exactly. 107 00:05:57,200 --> 00:05:59,359 Speaker 1: And you know, we also have to think outside of 108 00:05:59,400 --> 00:06:02,920 Speaker 1: the the sort of human male female scenario, right and 109 00:06:02,960 --> 00:06:06,000 Speaker 1: get down to the basic reality that I feel like 110 00:06:06,040 --> 00:06:10,000 Speaker 1: is is far more obvious when you start looking at 111 00:06:10,560 --> 00:06:13,640 Speaker 1: in the world of of insects and arachnids and a 112 00:06:13,640 --> 00:06:16,360 Speaker 1: few other species, and that is that the females are 113 00:06:16,480 --> 00:06:20,200 Speaker 1: the species and the male is just this uh essentially, 114 00:06:20,240 --> 00:06:26,040 Speaker 1: this mutation that's necessary to enable genetic diversity through sexual reproduction. 115 00:06:26,320 --> 00:06:30,080 Speaker 1: So he's he only has this one purpose anyway, He's 116 00:06:30,160 --> 00:06:35,280 Speaker 1: just this genetic material, heat seeking missile and aid in reproduction. 117 00:06:35,640 --> 00:06:40,080 Speaker 1: So why not eat him? Right? His job is done 118 00:06:40,120 --> 00:06:43,559 Speaker 1: and there's there that's it gets to be more complex question, 119 00:06:43,560 --> 00:06:46,320 Speaker 1: as will explore later, But you know it makes sense 120 00:06:46,360 --> 00:06:48,719 Speaker 1: if you just look at the pure math of the scenario. Yeah, 121 00:06:48,760 --> 00:06:50,640 Speaker 1: And to get even weirder. I mean, you might be 122 00:06:50,680 --> 00:06:52,799 Speaker 1: able to say that neither the male nor the female 123 00:06:52,920 --> 00:06:56,479 Speaker 1: is really the purpose of the species. The phenotype, the body, 124 00:06:57,000 --> 00:06:59,760 Speaker 1: none of that is the species. The species is a 125 00:07:00,040 --> 00:07:03,080 Speaker 1: mean pool. It's this abstract concept. It's really more of 126 00:07:03,120 --> 00:07:06,080 Speaker 1: a movement as opposed to a physical thing. Because yeah, 127 00:07:06,160 --> 00:07:10,000 Speaker 1: that it's not the little creatures that exist for especially 128 00:07:10,040 --> 00:07:14,120 Speaker 1: in the insect world, often very slim periods of time. 129 00:07:14,440 --> 00:07:19,320 Speaker 1: It is that that continued movement, genetic movement through time. Yeah, 130 00:07:19,320 --> 00:07:21,760 Speaker 1: but but especially the males. You might say, like if 131 00:07:22,080 --> 00:07:24,880 Speaker 1: if there is a sexual dimorphism in the species, a 132 00:07:25,000 --> 00:07:27,760 Speaker 1: different in body, a difference in body plans between male 133 00:07:27,800 --> 00:07:29,880 Speaker 1: and female, and it just you look at it and 134 00:07:29,920 --> 00:07:32,360 Speaker 1: you say, wow, it really looks like there's more going 135 00:07:32,400 --> 00:07:35,360 Speaker 1: into the female. She's bigger, she has more survival capacity. 136 00:07:35,360 --> 00:07:38,520 Speaker 1: It really sometimes can look to a human observer like, well, 137 00:07:38,640 --> 00:07:41,800 Speaker 1: that's the female is what the species is, and the 138 00:07:41,840 --> 00:07:45,080 Speaker 1: male is just sort of this thing that exists to mate. 139 00:07:45,280 --> 00:07:46,960 Speaker 1: And yeah, and I think you can make a pretty 140 00:07:46,960 --> 00:07:51,680 Speaker 1: strong case for that that the female is the primary 141 00:07:51,760 --> 00:07:55,480 Speaker 1: member of the species. Now already we're talking I think 142 00:07:55,560 --> 00:08:02,560 Speaker 1: in sort of perhaps unscientific terms, like what we're using anthropomorphization, 143 00:08:02,760 --> 00:08:06,320 Speaker 1: and we're using our our our sort of human judgment 144 00:08:06,440 --> 00:08:09,280 Speaker 1: of how things just seem to look to us, based 145 00:08:09,280 --> 00:08:13,040 Speaker 1: on the way we think about relationships between animals, probably 146 00:08:13,080 --> 00:08:16,440 Speaker 1: mostly based on the way we think about relationships between humans. 147 00:08:16,760 --> 00:08:19,760 Speaker 1: And this is sort of an inherent problem in studying 148 00:08:19,880 --> 00:08:24,800 Speaker 1: things like animal mating practices and reproduction and especially especially 149 00:08:24,880 --> 00:08:29,600 Speaker 1: sexual cannibalism. It we just can't help but infuse it 150 00:08:29,840 --> 00:08:32,560 Speaker 1: with all of the sort of social markers of how 151 00:08:32,679 --> 00:08:35,839 Speaker 1: we view relationships as humans. Yeah, and that's true of 152 00:08:36,040 --> 00:08:40,560 Speaker 1: not only consumers, readers, outsiders, true not only of science 153 00:08:40,559 --> 00:08:45,199 Speaker 1: communicators like like ourselves, but also scientific researchers themselves. And 154 00:08:45,280 --> 00:08:47,679 Speaker 1: there was actually a paper on this, Yeah, two thousand 155 00:08:47,760 --> 00:08:51,840 Speaker 1: ten paper Sexual Stereotypes the Case of Sexual Cannibalism. This 156 00:08:51,920 --> 00:08:55,520 Speaker 1: was from the UK's University of St Andrew's School of Biology. 157 00:08:55,559 --> 00:08:58,440 Speaker 1: They looked at about they looked at a larger sample 158 00:08:58,440 --> 00:09:00,280 Speaker 1: than they had to whittle it down to end up 159 00:09:00,280 --> 00:09:04,000 Speaker 1: looking at around two ten relevant papers dealing with sexual cannibalism, 160 00:09:04,080 --> 00:09:06,720 Speaker 1: and they found that females were more likely to be 161 00:09:07,000 --> 00:09:10,880 Speaker 1: to be described using active words and males with reactive words, 162 00:09:11,160 --> 00:09:13,240 Speaker 1: And then a number of the words used to describe 163 00:09:13,280 --> 00:09:17,920 Speaker 1: cannibalistic females were highly loaded, suggesting a negative stereotype of 164 00:09:18,360 --> 00:09:21,880 Speaker 1: sexually aggressive females. Uh. And then the males were more 165 00:09:21,920 --> 00:09:25,640 Speaker 1: likely to be described as as making a sacrifice, while 166 00:09:25,640 --> 00:09:30,000 Speaker 1: the females were just you know, voracious widows. Um, that's funny. 167 00:09:30,280 --> 00:09:32,400 Speaker 1: Voracious is a word I did see pop up in 168 00:09:32,440 --> 00:09:36,360 Speaker 1: the literature, in the scientific literature on sexual cannibalism a lot. 169 00:09:36,440 --> 00:09:38,120 Speaker 1: And and there are some good points to be made 170 00:09:38,120 --> 00:09:40,800 Speaker 1: about you know, even though this is sort of a 171 00:09:40,800 --> 00:09:43,160 Speaker 1: tendency that's hard to overcome. I know we're going to 172 00:09:43,280 --> 00:09:46,400 Speaker 1: do it in this episode plenty. We're gonna anthropomorphize. It's 173 00:09:46,440 --> 00:09:48,640 Speaker 1: just how we talk about things, how we talk about 174 00:09:48,679 --> 00:09:50,920 Speaker 1: it's how we understand the topics, how we conceptualize them 175 00:09:50,920 --> 00:09:52,760 Speaker 1: in our head. Uh. There is a good case to 176 00:09:52,800 --> 00:09:55,319 Speaker 1: be made. I think that scientists should do their best 177 00:09:55,360 --> 00:09:59,280 Speaker 1: to avoid this. And one simple reason is that these 178 00:09:59,360 --> 00:10:02,720 Speaker 1: kind of social, really charged words are vague. Yeah, you know, 179 00:10:02,920 --> 00:10:07,920 Speaker 1: they're not. They don't they don't deal in easily reproducible quantities. 180 00:10:07,960 --> 00:10:11,640 Speaker 1: So if somebody wants to redo your experiments somewhere else, 181 00:10:11,960 --> 00:10:15,480 Speaker 1: can they tell what you mean by voracious. I mean, 182 00:10:15,520 --> 00:10:17,920 Speaker 1: it seems like it makes more sense to just talk 183 00:10:17,960 --> 00:10:22,920 Speaker 1: about numerical conditions. So a spider that attacks this percentage 184 00:10:22,960 --> 00:10:27,920 Speaker 1: of prey within this you know, radius of range is 185 00:10:27,920 --> 00:10:30,839 Speaker 1: is voracious. Yeah. And then I mean, just overall, it's 186 00:10:30,920 --> 00:10:35,200 Speaker 1: detrimental to view a species normalcy through the lens of 187 00:10:35,200 --> 00:10:39,080 Speaker 1: our own species abnormality. So because I mean, for instance, 188 00:10:39,080 --> 00:10:41,400 Speaker 1: we can study ducks without going holy crap. Can you 189 00:10:41,440 --> 00:10:47,040 Speaker 1: imagine if humans late eggs like a duck. So it's 190 00:10:47,040 --> 00:10:49,440 Speaker 1: a different creature, it's a different species. It is an 191 00:10:49,440 --> 00:10:53,640 Speaker 1: inhuman thing. And I guess anytime I study insects, I 192 00:10:53,679 --> 00:10:58,320 Speaker 1: always come back, maybe problematically to um the line of 193 00:10:58,320 --> 00:11:02,160 Speaker 1: of Dr Brundle in The Lie talking about uh insect 194 00:11:02,280 --> 00:11:06,160 Speaker 1: politics and about how there are no insect politicians um, 195 00:11:06,320 --> 00:11:08,520 Speaker 1: which which I think it's a great line, not only 196 00:11:08,559 --> 00:11:10,800 Speaker 1: within the context of that film, but also in terms 197 00:11:10,840 --> 00:11:14,440 Speaker 1: of looking at any of these scenarios where something through 198 00:11:14,480 --> 00:11:17,680 Speaker 1: our lens, through our lens of human normalcy, maybe just 199 00:11:17,840 --> 00:11:21,000 Speaker 1: really horrific and monstrous. And we want to cast this 200 00:11:21,160 --> 00:11:25,240 Speaker 1: insect as a villain, and this as a poor suffering martyr, 201 00:11:25,480 --> 00:11:30,000 Speaker 1: but it is an utterly inhuman system and there's no 202 00:11:30,040 --> 00:11:32,199 Speaker 1: getting around that. I'm sorry, I'm not listening to you 203 00:11:32,200 --> 00:11:36,280 Speaker 1: because I'm imagining the fly with a duck instead of 204 00:11:36,280 --> 00:11:40,160 Speaker 1: a fly. So Seth Brundole gets transformed into part duck 205 00:11:40,360 --> 00:11:43,079 Speaker 1: and he's got he's uh, he's got a bill. Well, 206 00:11:43,120 --> 00:11:45,160 Speaker 1: you know, Howard the Duck and the Fly came out 207 00:11:45,160 --> 00:11:48,960 Speaker 1: in the same year. Yeah, oh wow, Yeah, that's a 208 00:11:49,000 --> 00:11:51,000 Speaker 1: good year for film, the year for film. In fact, 209 00:11:51,040 --> 00:11:53,040 Speaker 1: we just had a how Stuff Works Now article come 210 00:11:53,040 --> 00:11:55,720 Speaker 1: out on that Send all of your Howard the Duck 211 00:11:55,720 --> 00:11:58,760 Speaker 1: hate mail to blow the mind stuff Works dot com. 212 00:11:58,880 --> 00:12:01,400 Speaker 1: But no. But moving on from how weird it would 213 00:12:01,400 --> 00:12:04,440 Speaker 1: be if humans were part duck, we should look at 214 00:12:04,440 --> 00:12:07,160 Speaker 1: the evolution of sexual cannibalism. We're going to talk about 215 00:12:07,200 --> 00:12:10,560 Speaker 1: some specific cases later in this episode of species that 216 00:12:10,600 --> 00:12:13,200 Speaker 1: practice it and what we have learned from them in 217 00:12:13,240 --> 00:12:17,280 Speaker 1: recent studies. But where where do we typically see sexual 218 00:12:17,320 --> 00:12:20,160 Speaker 1: cannibalism in the animal kingdom? Like, how come you don't 219 00:12:20,320 --> 00:12:26,760 Speaker 1: usually see a female cat eat a male cat after sex? Well, 220 00:12:26,800 --> 00:12:30,360 Speaker 1: I mean there's some biting, I think sometimes, but no, 221 00:12:30,559 --> 00:12:33,640 Speaker 1: for the most part, we're looking at insects and arachnids, uh, 222 00:12:33,640 --> 00:12:36,600 Speaker 1: spiders and scorpions being the primary of research. There's some 223 00:12:36,640 --> 00:12:41,040 Speaker 1: insects such as such as manted mant manted species, and 224 00:12:41,080 --> 00:12:45,199 Speaker 1: I believe there are also some uh, some evidences suggests 225 00:12:45,240 --> 00:12:48,160 Speaker 1: that there are some gastropod and copio pod cases. But 226 00:12:48,600 --> 00:12:50,560 Speaker 1: in the for the most part though, we're dealing with 227 00:12:51,120 --> 00:12:55,680 Speaker 1: especially with spiders and scorpions and and and mantis species. 228 00:12:55,720 --> 00:13:00,480 Speaker 1: We're dealing with highly solitary predatory animals, which I think 229 00:13:00,559 --> 00:13:05,440 Speaker 1: is key, especially regarding some of the theories regarding sexual cannibalism. Right, 230 00:13:05,520 --> 00:13:07,520 Speaker 1: so if you want to keep in mind that they 231 00:13:07,520 --> 00:13:11,160 Speaker 1: typically aren't the most social animal rights that eat each 232 00:13:11,160 --> 00:13:14,600 Speaker 1: other after sex, this might help inform our ideas about 233 00:13:14,640 --> 00:13:18,640 Speaker 1: how this evolved. Yeah, these are two anthropomorphizes. These are 234 00:13:18,760 --> 00:13:23,120 Speaker 1: loane killers. These are wanderers that are just out there 235 00:13:23,160 --> 00:13:26,000 Speaker 1: on the highway eating what they need to eat to survive. 236 00:13:26,240 --> 00:13:28,520 Speaker 1: I'd say, even if you don't want to infuse it 237 00:13:28,559 --> 00:13:31,160 Speaker 1: with with human concepts of good and evil, you could 238 00:13:31,160 --> 00:13:35,520 Speaker 1: easily say that sexual cannibalism is a chaotic, neutral trait. Yeah, yeah, 239 00:13:35,520 --> 00:13:40,520 Speaker 1: I would think so so m but but so, like 240 00:13:40,600 --> 00:13:42,679 Speaker 1: we've said, it is rare in the animal kingdom. You 241 00:13:42,720 --> 00:13:46,000 Speaker 1: don't see it in most species, and why is that? Well? 242 00:13:46,200 --> 00:13:48,080 Speaker 1: On one on one level, I think we definitely have 243 00:13:48,160 --> 00:13:51,720 Speaker 1: to again look to the solitary predatory nature of these 244 00:13:51,720 --> 00:13:56,160 Speaker 1: particular species. And then there's also just cannibalism as a whole. 245 00:13:56,200 --> 00:14:01,880 Speaker 1: If cannibalism is too essential to the ecs, then you 246 00:14:02,920 --> 00:14:06,800 Speaker 1: it eventually is going to have an economically detrimental effect. Right, 247 00:14:07,520 --> 00:14:13,240 Speaker 1: So imagine your standard sexual cannibalistic interaction. A female spider 248 00:14:13,280 --> 00:14:16,600 Speaker 1: as a web. Male spider approaches the web, climbs onto 249 00:14:16,600 --> 00:14:19,440 Speaker 1: the web, mates with the female, may or may not 250 00:14:19,600 --> 00:14:23,880 Speaker 1: successfully impregnate her, and the female eats the eats the 251 00:14:23,920 --> 00:14:27,600 Speaker 1: male spider kills him, drains all his fluids, gets energy 252 00:14:27,640 --> 00:14:30,120 Speaker 1: from it. But the male spider can mate no more. 253 00:14:30,760 --> 00:14:33,520 Speaker 1: His days of passing on his genes are now done. 254 00:14:33,960 --> 00:14:38,200 Speaker 1: So this interaction works out pretty well for the female spider. 255 00:14:38,280 --> 00:14:40,120 Speaker 1: I mean, so you can see why her genes would 256 00:14:40,160 --> 00:14:43,720 Speaker 1: encourage such an interaction. But the question is why would 257 00:14:43,720 --> 00:14:47,680 Speaker 1: the male do that? Why why does it uh genetically 258 00:14:47,800 --> 00:14:50,640 Speaker 1: can I mean again we're using anthropomorphic terms like consent, 259 00:14:50,760 --> 00:14:53,840 Speaker 1: but I would say, why do its genes consent to 260 00:14:53,960 --> 00:14:58,840 Speaker 1: this interaction where it has a strong chance of being eaten? Indeed, 261 00:14:58,880 --> 00:15:01,000 Speaker 1: that's one of the big questions here, and one of 262 00:15:01,000 --> 00:15:04,000 Speaker 1: the questions that a number of these theories um of 263 00:15:04,080 --> 00:15:08,760 Speaker 1: sexual cannibism evolution explore. So at this point we should 264 00:15:08,800 --> 00:15:12,600 Speaker 1: really start talking about what those theories are and uh, 265 00:15:12,640 --> 00:15:15,160 Speaker 1: and then break into some of the examples that explore 266 00:15:15,240 --> 00:15:18,000 Speaker 1: how they work. Yeah. So there are several conflicting or 267 00:15:18,040 --> 00:15:22,600 Speaker 1: competing hypotheses about the evolution of sexual cannibalism, and we 268 00:15:22,600 --> 00:15:24,840 Speaker 1: should say that more than one can be true in 269 00:15:24,840 --> 00:15:28,479 Speaker 1: different cases, right, Yeah, there's some overlap here for sure. Yeah, 270 00:15:28,480 --> 00:15:30,280 Speaker 1: But I think one thing to keep in mind during 271 00:15:30,320 --> 00:15:34,360 Speaker 1: these explanations is that there are different ways that evolution 272 00:15:34,520 --> 00:15:38,040 Speaker 1: can pay for a trait. Let's say you have a 273 00:15:38,080 --> 00:15:41,000 Speaker 1: trait that makes you there's something about your brain that 274 00:15:41,040 --> 00:15:44,120 Speaker 1: makes you really likely to kick people in the face 275 00:15:44,280 --> 00:15:47,680 Speaker 1: at the first time you meet them. Um, there there 276 00:15:47,680 --> 00:15:49,920 Speaker 1: are two ways that could come through in your genes 277 00:15:50,120 --> 00:15:52,720 Speaker 1: according to evolutionary theory. One one way is that the 278 00:15:52,760 --> 00:15:56,640 Speaker 1: trade itself is beneficial. Overall, people who kick people in 279 00:15:56,680 --> 00:15:59,280 Speaker 1: the face first time they meet just happen to have 280 00:15:59,440 --> 00:16:02,200 Speaker 1: more kids than people who don't, So it could be beneficial, 281 00:16:02,960 --> 00:16:05,520 Speaker 1: or it could it be it could be an unintended 282 00:16:05,600 --> 00:16:08,840 Speaker 1: side effect of a very beneficial trait. So it could 283 00:16:08,840 --> 00:16:11,960 Speaker 1: be that there's actually not a good there's nothing good 284 00:16:11,960 --> 00:16:13,960 Speaker 1: that comes from kicking people in the face when you 285 00:16:14,000 --> 00:16:16,280 Speaker 1: first meet them, But you're really good at kicking people 286 00:16:16,320 --> 00:16:18,880 Speaker 1: in the face the rest of the time, exactly, So 287 00:16:18,920 --> 00:16:22,680 Speaker 1: you're much much better at defending yourself against predators. So 288 00:16:22,840 --> 00:16:26,120 Speaker 1: you just happened to be kicking crazy and and this 289 00:16:26,200 --> 00:16:27,920 Speaker 1: is just sort of and you're so good at defending 290 00:16:27,920 --> 00:16:31,480 Speaker 1: yourself for predators, this kicking genes survives even though it's 291 00:16:31,520 --> 00:16:34,760 Speaker 1: not particularly helpful in the case of kicking strangers in 292 00:16:34,760 --> 00:16:38,360 Speaker 1: the face when you first meet them. So the first 293 00:16:38,400 --> 00:16:42,680 Speaker 1: of these several theories we're gonna mention here is adaptive foraging. 294 00:16:42,840 --> 00:16:47,080 Speaker 1: So this one's pretty basic. Starving female mates the male 295 00:16:47,200 --> 00:16:50,320 Speaker 1: is there, she's hungry, she's gonna need energy. Why not 296 00:16:50,440 --> 00:16:53,480 Speaker 1: go ahead and eat him during either during the act 297 00:16:53,560 --> 00:16:57,560 Speaker 1: or immediately thereafter. Eating the male increases her chance of survival, 298 00:16:58,200 --> 00:17:01,800 Speaker 1: gives her a meal based power up uh and as 299 00:17:01,880 --> 00:17:04,080 Speaker 1: a as a as a sort of side effect to 300 00:17:04,720 --> 00:17:08,000 Speaker 1: her lover can't help produce any spawn that end up 301 00:17:08,080 --> 00:17:11,439 Speaker 1: rivaling her own resources. But essentially it comes down to 302 00:17:12,200 --> 00:17:16,160 Speaker 1: I'm just I'm adapting to the what food is available 303 00:17:16,200 --> 00:17:17,720 Speaker 1: to me, and here is a meal in front of 304 00:17:17,720 --> 00:17:19,880 Speaker 1: me right now. Okay, so this is sort of the 305 00:17:19,880 --> 00:17:24,919 Speaker 1: the opportunism hypothesis. It's just saying that, like, look, you know, 306 00:17:25,240 --> 00:17:28,040 Speaker 1: the meal is worth it essentially right now. Some of 307 00:17:28,040 --> 00:17:31,480 Speaker 1: the critics argue that the males in many of these cases, 308 00:17:31,520 --> 00:17:34,520 Speaker 1: they actually make pretty poor meals. They're not really gonna 309 00:17:34,760 --> 00:17:38,639 Speaker 1: make or break the female. But then there are cases 310 00:17:38,680 --> 00:17:41,480 Speaker 1: where they say that, hey, the female is actually able 311 00:17:41,520 --> 00:17:45,879 Speaker 1: to acquire crucial proteins or lipids from the male that 312 00:17:46,000 --> 00:17:48,440 Speaker 1: she eats that she might not otherwise get from her 313 00:17:48,480 --> 00:17:52,000 Speaker 1: standard predatory diet. Okay, So I'm thinking that this is 314 00:17:52,040 --> 00:17:55,720 Speaker 1: saying that the sexual cannibalism is itself an adaptation. It 315 00:17:56,240 --> 00:17:59,800 Speaker 1: is itself a trait that is encouraged because overall it's 316 00:17:59,840 --> 00:18:03,159 Speaker 1: been official to the spider gene pool. Yeah, not to 317 00:18:03,200 --> 00:18:05,000 Speaker 1: the gene pool. I mean, it's I'm not taking a 318 00:18:05,000 --> 00:18:07,720 Speaker 1: species level evolution here. It would be beneficial to the 319 00:18:07,760 --> 00:18:11,080 Speaker 1: genes themselves. In the animals that do it. Yeah, the 320 00:18:11,320 --> 00:18:14,719 Speaker 1: females who eat their male have just one little power 321 00:18:14,800 --> 00:18:17,439 Speaker 1: up over those who that do not. Yeah, And The 322 00:18:17,520 --> 00:18:19,800 Speaker 1: idea here is that this is very much a kicking 323 00:18:19,800 --> 00:18:22,760 Speaker 1: people in the face the first time you meet them, right, 324 00:18:22,800 --> 00:18:26,640 Speaker 1: it's a good thing. Okay. But then there's another hypothesis 325 00:18:26,720 --> 00:18:28,199 Speaker 1: that is one I've read about in some of the 326 00:18:28,200 --> 00:18:30,359 Speaker 1: studies I looked up here. It's the sort of I 327 00:18:30,359 --> 00:18:34,199 Speaker 1: think it's turned the aggressive spill over hypothesis. Uh. And 328 00:18:34,280 --> 00:18:36,920 Speaker 1: this is more that other idea we were talking about 329 00:18:36,920 --> 00:18:39,639 Speaker 1: that there are some traits that are very beneficial, but 330 00:18:39,720 --> 00:18:44,160 Speaker 1: they encourage side effects. So one trait, for example, might 331 00:18:44,200 --> 00:18:47,600 Speaker 1: be that a that a female is very aggressive in 332 00:18:47,720 --> 00:18:50,919 Speaker 1: chasing down prey. It has genes that lead it to 333 00:18:51,000 --> 00:18:53,920 Speaker 1: be a total killer. It's just a go getter. It 334 00:18:54,040 --> 00:18:57,320 Speaker 1: sees something moving, it's like gonna eat that. Uh. And 335 00:18:57,440 --> 00:19:01,399 Speaker 1: this might be very beneficial to this creature when it's 336 00:19:01,440 --> 00:19:04,200 Speaker 1: trying to survive in the wild. It's it's very good 337 00:19:04,200 --> 00:19:07,040 Speaker 1: at chasing down things, killing them and eating them. But 338 00:19:07,400 --> 00:19:11,520 Speaker 1: these same genes also sometimes they get applied in the 339 00:19:11,560 --> 00:19:15,200 Speaker 1: wrong direction. Yeah, like to anthromorphize the situation. It's it's 340 00:19:15,200 --> 00:19:19,159 Speaker 1: like imagining that the spider or the scorpion in the scenario. 341 00:19:19,160 --> 00:19:23,480 Speaker 1: It's like a a female wrestler who in the act 342 00:19:23,520 --> 00:19:26,280 Speaker 1: of making love cannot help, like the muscle memory, just 343 00:19:26,400 --> 00:19:28,320 Speaker 1: an instincts kick in and she has to throw a 344 00:19:28,359 --> 00:19:31,960 Speaker 1: suplex or two or put somebody in a submission. Hold. Um, 345 00:19:32,000 --> 00:19:34,720 Speaker 1: this is just the female in this scenario is just 346 00:19:34,840 --> 00:19:39,000 Speaker 1: so aggressive, just so just amped up and ready to go, 347 00:19:39,480 --> 00:19:42,920 Speaker 1: that the predatory nature just kicks in and she ends 348 00:19:43,000 --> 00:19:46,160 Speaker 1: up consuming the part or all of the male. Yeah. Now, 349 00:19:46,280 --> 00:19:48,880 Speaker 1: is there any evidence for this? I think there's some. Yeah, 350 00:19:48,920 --> 00:19:51,760 Speaker 1: it depends. I mean in some species of spider. Yes, 351 00:19:51,840 --> 00:19:56,320 Speaker 1: researchers have observed higher sexual cannibalism rates among females that 352 00:19:56,480 --> 00:20:01,000 Speaker 1: also attacked prey at a faster rate than other females 353 00:20:01,000 --> 00:20:03,040 Speaker 1: they've observed I want to talk about one of these 354 00:20:03,040 --> 00:20:06,320 Speaker 1: studies in a bit. Okay, but then another species there's 355 00:20:06,320 --> 00:20:09,640 Speaker 1: no correlation. So that's the That's one of the issues too, 356 00:20:09,680 --> 00:20:11,600 Speaker 1: is you're dealing with You're not dealing with just one 357 00:20:11,680 --> 00:20:18,920 Speaker 1: species that's engaging in sexual cannibalism. You're dealing in multiple species. Uh, 358 00:20:19,359 --> 00:20:22,520 Speaker 1: some are rather diverse from one another that have in 359 00:20:22,560 --> 00:20:27,720 Speaker 1: many cases independently evolved this adaptation. Yeah. Now, one one 360 00:20:27,800 --> 00:20:30,320 Speaker 1: hypothesis I saw just kind of mentioned on the internet. 361 00:20:30,359 --> 00:20:32,440 Speaker 1: But I didn't see in any of the scientific literature 362 00:20:32,440 --> 00:20:35,639 Speaker 1: I was looking at was the mistaken identity hypothesis. I 363 00:20:35,680 --> 00:20:38,320 Speaker 1: couldn't tell if there's really anything to this the I 364 00:20:38,359 --> 00:20:40,479 Speaker 1: saw it mentioned. I mean, the basic idea here is 365 00:20:41,240 --> 00:20:44,000 Speaker 1: the female is saying, are you food? Are you my lover? Well, 366 00:20:44,080 --> 00:20:45,320 Speaker 1: let me just take a bite out of you. I 367 00:20:45,320 --> 00:20:47,040 Speaker 1: can't tell. I guess you're my enemy. I'll just bite 368 00:20:47,080 --> 00:20:50,040 Speaker 1: into you. Uh. The only place that I saw this, 369 00:20:49,760 --> 00:20:51,720 Speaker 1: and this is the person who kicks people in the 370 00:20:51,760 --> 00:20:55,040 Speaker 1: face because he's near sighted, right exactly, enemy or lover. 371 00:20:55,480 --> 00:20:58,600 Speaker 1: I think enemy, I'm gonna kick Yeah. So the only 372 00:20:59,000 --> 00:21:01,479 Speaker 1: place I saw this mint and was in um uh 373 00:21:01,640 --> 00:21:07,160 Speaker 1: Knwyn Blake Subtle's paper The Evolution of Sexual Cannibalism. Uh. 374 00:21:07,240 --> 00:21:10,000 Speaker 1: And he said that there's just no empirical evidence to 375 00:21:10,040 --> 00:21:14,880 Speaker 1: support this theory. Uh. For instance, he says that the 376 00:21:14,880 --> 00:21:18,560 Speaker 1: the Fight a Puss Spiders offer a strong argument against 377 00:21:18,640 --> 00:21:23,720 Speaker 1: mistaken identity because, particularly among the Salta sids, you have 378 00:21:23,800 --> 00:21:29,240 Speaker 1: the highest visual acuity of all aractans. That's I think 379 00:21:29,240 --> 00:21:32,320 Speaker 1: that's jumping spiders right. Yes, And he tells us that 380 00:21:32,359 --> 00:21:36,000 Speaker 1: when you take into account um cannibalism during and after 381 00:21:36,200 --> 00:21:39,160 Speaker 1: copulation that would seem to even further eliminate the possibility. 382 00:21:39,200 --> 00:21:42,199 Speaker 1: So that the idea here is that, yeah, they're not 383 00:21:42,320 --> 00:21:46,720 Speaker 1: just blind dummies in these cases. They they have senses 384 00:21:46,800 --> 00:21:50,520 Speaker 1: available to them to determine if this is a member 385 00:21:50,520 --> 00:21:56,800 Speaker 1: of their own species or a solid outsider prey species. Ye. Now, 386 00:21:56,840 --> 00:22:01,479 Speaker 1: of course, one other hypothesis we could say competes with 387 00:22:01,520 --> 00:22:04,600 Speaker 1: these and and maybe sometimes overlaps with them, is that 388 00:22:04,680 --> 00:22:08,520 Speaker 1: it's just it's sexual selection. Yeah, it's it's females being 389 00:22:08,600 --> 00:22:12,160 Speaker 1: choosy about which males they mate with or whether intentionally 390 00:22:12,240 --> 00:22:17,320 Speaker 1: or not um and this is encouraging pairing with stronger 391 00:22:17,440 --> 00:22:21,240 Speaker 1: or fitter or more appropriate males through a tendency to 392 00:22:21,359 --> 00:22:24,000 Speaker 1: eat the males. Yeah, it's just it's kind of a 393 00:22:24,240 --> 00:22:27,240 Speaker 1: it's not it's not me, it's you scenario. So I'm 394 00:22:27,240 --> 00:22:30,440 Speaker 1: going to eat you instead. You're not really uh, you're 395 00:22:30,480 --> 00:22:34,280 Speaker 1: not really husband material. Maybe you're more meal material. Right. 396 00:22:37,680 --> 00:22:40,680 Speaker 1: So yeah, that the basic hypotheses here entails the notion 397 00:22:40,720 --> 00:22:44,520 Speaker 1: that the cannibal female just rejects unacceptable males and eats them. 398 00:22:44,800 --> 00:22:47,639 Speaker 1: And it's smaller unfit males are better suited as meals. 399 00:22:47,880 --> 00:22:50,680 Speaker 1: Larger ones are the better mates, though you also see 400 00:22:50,720 --> 00:22:56,680 Speaker 1: this reversed in some cases with females favoring smaller mates. Uh. Again, 401 00:22:56,720 --> 00:22:58,920 Speaker 1: it kind of depends on the species, right. Well, as 402 00:22:58,960 --> 00:23:01,760 Speaker 1: we know from so many great evolutionary biologist before, it's 403 00:23:01,800 --> 00:23:06,119 Speaker 1: not always the strongest, that's the fittest. The bigger doesn't 404 00:23:06,119 --> 00:23:08,879 Speaker 1: always necessarily mean better. Fitter can mean a lot of 405 00:23:08,920 --> 00:23:12,800 Speaker 1: different things in different environments, And the environment can include 406 00:23:12,840 --> 00:23:17,600 Speaker 1: the sexual selection environment, the gene environment in which you're competing. Yeah, 407 00:23:17,680 --> 00:23:21,440 Speaker 1: and the mere fact that both varieties survive often indicates 408 00:23:21,480 --> 00:23:25,280 Speaker 1: that both are valued forms of that species. Uh. And 409 00:23:25,280 --> 00:23:28,639 Speaker 1: there are a number of different mate choice splinter theories 410 00:23:28,680 --> 00:23:33,520 Speaker 1: as well, um running the anthropomorphic gamut for all the 411 00:23:33,560 --> 00:23:37,280 Speaker 1: reasons you might you know, mate reject or cannibalize your 412 00:23:37,320 --> 00:23:39,880 Speaker 1: spider lover so that you have it. Are those are 413 00:23:39,920 --> 00:23:44,119 Speaker 1: the basic theories regarding sexual capitalism. All right, So now 414 00:23:44,119 --> 00:23:45,639 Speaker 1: I think it's time to take a quick break. But 415 00:23:45,680 --> 00:23:47,240 Speaker 1: when we come back, we're going to take a look 416 00:23:47,280 --> 00:23:59,000 Speaker 1: at our rogues gallery of cannibals. All right, we're back. 417 00:23:59,280 --> 00:24:01,680 Speaker 1: Who do we have for Joe? Well, I thought it 418 00:24:01,680 --> 00:24:04,879 Speaker 1: would be interesting because of a specific study I found 419 00:24:05,080 --> 00:24:10,280 Speaker 1: to look at the cannibalistic burrowing wolf spider, the Lycosa Hispanica. 420 00:24:11,760 --> 00:24:15,200 Speaker 1: And this is from a paper called does female personality 421 00:24:15,320 --> 00:24:19,480 Speaker 1: determine mate choice through sexual Cannibalism? It was published in 422 00:24:19,480 --> 00:24:23,760 Speaker 1: the journal Ethology in and Uh. It was carried out 423 00:24:23,800 --> 00:24:27,520 Speaker 1: by some research group at the Experimental Station of arid 424 00:24:27,600 --> 00:24:30,959 Speaker 1: Zones E Z A C, S I C in Spain. 425 00:24:31,560 --> 00:24:35,320 Speaker 1: And and here's what's going on. Sometimes you want to 426 00:24:35,359 --> 00:24:38,520 Speaker 1: eat your mate, but you cannot wait for the mating. 427 00:24:39,760 --> 00:24:43,639 Speaker 1: This is a problem because obviously, so we've talked about 428 00:24:43,680 --> 00:24:47,000 Speaker 1: the benefits for the female of sexual cannibalism. She gets 429 00:24:47,040 --> 00:24:49,560 Speaker 1: to mate, and she gets to pass on her genes, 430 00:24:49,720 --> 00:24:52,480 Speaker 1: and she also gets a meal. And we've been debating 431 00:24:52,520 --> 00:24:55,400 Speaker 1: the benefits for the male. But what if the female 432 00:24:55,720 --> 00:24:58,720 Speaker 1: eats she wants to eat the mate so bad that 433 00:24:58,800 --> 00:25:02,840 Speaker 1: she eats him before where they mate. I mean, that 434 00:25:02,920 --> 00:25:07,600 Speaker 1: seems like a maladaptive It would seems like it's gotten 435 00:25:07,640 --> 00:25:10,280 Speaker 1: out of control here. Yeah, And what they found is 436 00:25:10,320 --> 00:25:15,919 Speaker 1: that this happens a lot. Actually, So sometimes this specific tarantula, 437 00:25:16,040 --> 00:25:19,399 Speaker 1: this wolf spider, doesn't even wait for sex before eating 438 00:25:19,400 --> 00:25:23,560 Speaker 1: the potential mate. So why is that what determines if 439 00:25:23,560 --> 00:25:28,280 Speaker 1: the female wolf spider attacks a potential mate before the mating. 440 00:25:29,119 --> 00:25:31,600 Speaker 1: Is it how hungry she is? If so, this would 441 00:25:31,600 --> 00:25:36,240 Speaker 1: support the adaptive foraging hypothesis perhaps, or is it her 442 00:25:36,280 --> 00:25:39,159 Speaker 1: personality and if that's the case, it might support the 443 00:25:39,160 --> 00:25:42,959 Speaker 1: aggressive spillover. Is it the fitness of the male. This 444 00:25:43,040 --> 00:25:46,680 Speaker 1: might support some form of sexual selection or mate choice. 445 00:25:47,880 --> 00:25:50,879 Speaker 1: So the researchers decided to try to isolate these and 446 00:25:51,160 --> 00:25:53,240 Speaker 1: figure out which one is the most likely. So they 447 00:25:53,320 --> 00:25:56,240 Speaker 1: studied a group of female wolf spiders to see how 448 00:25:56,280 --> 00:26:00,280 Speaker 1: aggressive they were in feeding. And some were in mainly 449 00:26:00,320 --> 00:26:03,479 Speaker 1: aggressive that they were just going to town immediately on 450 00:26:03,520 --> 00:26:07,520 Speaker 1: any prey such as beatles, while others were more cautious 451 00:26:07,960 --> 00:26:12,560 Speaker 1: or they used the term docile, which I thought was funny. 452 00:26:12,640 --> 00:26:15,680 Speaker 1: Essentially more reticent hunters. They just didn't jump on prey 453 00:26:15,800 --> 00:26:19,000 Speaker 1: quite as quickly. And then they took these same females 454 00:26:19,040 --> 00:26:22,440 Speaker 1: they had studied and offered the females a random selection 455 00:26:22,520 --> 00:26:26,240 Speaker 1: of males for mating to see what would happen. Uh, 456 00:26:26,240 --> 00:26:29,320 Speaker 1: And you know what, the female personality actually seemed to 457 00:26:29,320 --> 00:26:30,960 Speaker 1: play a big role. So I want to read a 458 00:26:31,040 --> 00:26:34,200 Speaker 1: quote from a press release by one of the study authors, 459 00:26:34,240 --> 00:26:39,359 Speaker 1: Reuben robin Ada bueno uh, And the author said more 460 00:26:39,400 --> 00:26:43,840 Speaker 1: cannibalistic females were also more voracious towards their prey and 461 00:26:43,880 --> 00:26:47,280 Speaker 1: thus better nourished. This is surprising since they have more 462 00:26:47,400 --> 00:26:51,399 Speaker 1: nutritive resources to invest in their offspring before finding the 463 00:26:51,480 --> 00:26:55,520 Speaker 1: first males, and then said their priority should be ensuring 464 00:26:55,560 --> 00:26:59,040 Speaker 1: the firm spertilization of their eggs instead of eliminating their 465 00:26:59,040 --> 00:27:02,600 Speaker 1: potential donors. So this is kind of counterintuitive. You might 466 00:27:02,600 --> 00:27:05,680 Speaker 1: expect that the hungry or the female, the more likely 467 00:27:06,080 --> 00:27:08,959 Speaker 1: she would eat the male, but that's not what they found. 468 00:27:09,280 --> 00:27:12,680 Speaker 1: And the more aggressive females they pounced on the prey more, 469 00:27:12,800 --> 00:27:17,400 Speaker 1: they also ate more, They were less hungry, and they 470 00:27:17,440 --> 00:27:20,000 Speaker 1: were more likely to attack, kill, and eat the males. 471 00:27:21,320 --> 00:27:24,480 Speaker 1: So it sounds a little bit more like aggressive spill 472 00:27:24,520 --> 00:27:27,600 Speaker 1: over to me. Yeah. So, unless it's an aggressive spill over, 473 00:27:27,680 --> 00:27:32,879 Speaker 1: it would seem to be evolutionarily counterintuitive. She she's well nourished, 474 00:27:32,920 --> 00:27:36,560 Speaker 1: she should be prioritizing the fertilization of her eggs. Instead, 475 00:27:36,600 --> 00:27:40,080 Speaker 1: she just kills and eats her potential mates. But this 476 00:27:40,160 --> 00:27:43,679 Speaker 1: makes it look like baseline predation tendencies play a larger 477 00:27:43,800 --> 00:27:47,040 Speaker 1: role in whether or not the male gets eaten. Uh, 478 00:27:47,040 --> 00:27:49,880 Speaker 1: though you could possibly also look at this and interpret 479 00:27:49,960 --> 00:27:53,080 Speaker 1: it as a form of mate testing, Like you know, 480 00:27:53,160 --> 00:27:55,560 Speaker 1: the weaker males are the ones who are more likely 481 00:27:55,640 --> 00:28:00,560 Speaker 1: to get eaten. Alright. The next one you have here 482 00:28:00,680 --> 00:28:05,840 Speaker 1: is the raft spider, and this is UH Dolomedes fimbriatis. 483 00:28:06,080 --> 00:28:07,960 Speaker 1: And according to a two thousand fifteen study from the 484 00:28:08,040 --> 00:28:12,160 Speaker 1: University of Melbourne, these spiders do seem to be testing 485 00:28:12,240 --> 00:28:15,160 Speaker 1: the males and this would be mate fitness rather than 486 00:28:15,200 --> 00:28:18,520 Speaker 1: engaging in an aggressive spill over. Okay, how does this work? Well, 487 00:28:18,640 --> 00:28:21,080 Speaker 1: this is how they they They studied it. They watched 488 00:28:21,160 --> 00:28:24,240 Speaker 1: a bunch of spiders mate, of course, yes, they watched Yeah. 489 00:28:24,280 --> 00:28:27,560 Speaker 1: The first trial consisted of eleven saw that eleven of 490 00:28:27,600 --> 00:28:32,600 Speaker 1: sixteen females copulated, then attacked the males during or immediately 491 00:28:32,640 --> 00:28:36,359 Speaker 1: after copulation. Uh. Four of these attacks were fatal. Then 492 00:28:36,400 --> 00:28:38,840 Speaker 1: they did a second trial where six of eight females 493 00:28:38,840 --> 00:28:42,520 Speaker 1: that copulated attacked the males with two fatalities. So this 494 00:28:42,600 --> 00:28:45,520 Speaker 1: is interesting even in these uh. I think one thing 495 00:28:45,520 --> 00:28:47,840 Speaker 1: we should point out is that even in these species 496 00:28:47,840 --> 00:28:51,800 Speaker 1: that practice sexual cannibalism, it doesn't always happen, right, Yeah, 497 00:28:52,200 --> 00:28:56,200 Speaker 1: So in these cases, aggression level did not seem to 498 00:28:56,200 --> 00:28:58,840 Speaker 1: play a factor. So again they're they're looking at how 499 00:28:58,880 --> 00:29:02,000 Speaker 1: aggressive a hunters. This female appear to be outside the 500 00:29:02,000 --> 00:29:07,320 Speaker 1: context of mating. Rather male size, female age, and her 501 00:29:07,440 --> 00:29:11,280 Speaker 1: virginity seem to be more important factors, So females were 502 00:29:11,360 --> 00:29:14,800 Speaker 1: marginally more likely to attack smaller males. I don't know 503 00:29:14,840 --> 00:29:17,480 Speaker 1: if there's another word for this, but I kept seeing 504 00:29:17,480 --> 00:29:21,040 Speaker 1: this pop up over and over again. The virginity of 505 00:29:21,080 --> 00:29:24,240 Speaker 1: a spider. It just seems like it would that seems 506 00:29:24,280 --> 00:29:27,280 Speaker 1: like such a human word. Uh, Like it's weird to 507 00:29:27,320 --> 00:29:29,320 Speaker 1: think of a spider. I don't know, it would just 508 00:29:29,360 --> 00:29:31,320 Speaker 1: seem to make more sense to say, a spider who 509 00:29:31,400 --> 00:29:34,600 Speaker 1: had not yet made it. Yeah, spider virginity, or certainly 510 00:29:34,720 --> 00:29:37,480 Speaker 1: virginity of a spider sounds like a wonderful name for 511 00:29:37,560 --> 00:29:42,560 Speaker 1: a short horror collection, but actually will explore it in 512 00:29:42,600 --> 00:29:45,160 Speaker 1: a in another example I'm gonna get to in a bit, 513 00:29:45,480 --> 00:29:49,560 Speaker 1: you'll see where spider virginity, for lack of a better word, 514 00:29:49,840 --> 00:29:53,960 Speaker 1: does become more of an important consideration in sexual cannibalism. Yeah. Now, 515 00:29:54,160 --> 00:29:58,360 Speaker 1: one other interesting consideration to take into account is the 516 00:29:58,680 --> 00:30:04,200 Speaker 1: male decision in making process in sexual cannibalism cases. So 517 00:30:04,200 --> 00:30:08,600 Speaker 1: So a male is approaching a potential mate. He I 518 00:30:08,640 --> 00:30:11,120 Speaker 1: want to say he knows. I mean again, it's an insect, 519 00:30:11,200 --> 00:30:14,200 Speaker 1: so he probably doesn't really consciously know, but something about 520 00:30:14,320 --> 00:30:19,360 Speaker 1: his behavioral programming quote knows that he might get eaten 521 00:30:19,640 --> 00:30:22,480 Speaker 1: in some scenarios. So he has to do a kind 522 00:30:22,520 --> 00:30:27,560 Speaker 1: of behavioral cost benefit analysis. What what makes a delicious 523 00:30:27,680 --> 00:30:31,360 Speaker 1: bachelor insects decide to roll the dice with a hungry 524 00:30:31,400 --> 00:30:34,880 Speaker 1: female in the case of something like a praying mantis, 525 00:30:34,880 --> 00:30:38,760 Speaker 1: where the female in many cases eats the male during 526 00:30:38,880 --> 00:30:43,040 Speaker 1: or after sex. So there's a paper published in Plos 527 00:30:43,080 --> 00:30:46,600 Speaker 1: one that explores these decision factors and make choice in 528 00:30:46,640 --> 00:30:50,720 Speaker 1: sexual cannibalism UH in praying mantis is is called low 529 00:30:50,800 --> 00:30:55,920 Speaker 1: mate encounter rate increases male risk taking in sexually cannibalistic 530 00:30:56,040 --> 00:30:59,800 Speaker 1: praying mantis. UM. So you've got a male of a 531 00:31:00,040 --> 00:31:04,400 Speaker 1: ring mantis species like tin Odera sinensis and this is 532 00:31:04,440 --> 00:31:07,000 Speaker 1: this is a common praying mantis. I think it's referred 533 00:31:07,000 --> 00:31:10,720 Speaker 1: to as Chinese mantis. But it UH it has to 534 00:31:10,760 --> 00:31:14,239 Speaker 1: make a calculation of risk versus reward when approaching a female. Now, 535 00:31:14,240 --> 00:31:17,000 Speaker 1: I've read in one source that about sixteen percent of 536 00:31:17,040 --> 00:31:20,200 Speaker 1: the time a male of this species copulates with a 537 00:31:20,240 --> 00:31:23,640 Speaker 1: female in the wild, he gets slaughtered and eaten. So 538 00:31:24,320 --> 00:31:26,880 Speaker 1: those aren't good numbers. I mean, you wouldn't want to 539 00:31:26,920 --> 00:31:29,920 Speaker 1: copulate if you've got slaughtered sixteen percent of the time. 540 00:31:30,480 --> 00:31:32,520 Speaker 1: Uh So there's a chance of getting eaten, But of 541 00:31:32,560 --> 00:31:35,760 Speaker 1: course there's also the positive, a chance of reproducing. So 542 00:31:35,800 --> 00:31:38,600 Speaker 1: how does the male decide whether to roll the dice? 543 00:31:39,120 --> 00:31:41,600 Speaker 1: And the authors of this study point out two major 544 00:31:41,640 --> 00:31:45,640 Speaker 1: factors to consider. Number one is the level of predatory 545 00:31:45,920 --> 00:31:49,400 Speaker 1: risk imposed by the females, so some females are more 546 00:31:49,480 --> 00:31:52,240 Speaker 1: likely to eat you than other ones. And number two 547 00:31:52,680 --> 00:31:56,040 Speaker 1: is the frequency of mating opportunities for the males. How 548 00:31:56,040 --> 00:31:59,400 Speaker 1: many chances has this male had to copulate with other females. 549 00:32:00,360 --> 00:32:04,000 Speaker 1: So to study these things, the researchers artificially controlled the 550 00:32:04,080 --> 00:32:08,120 Speaker 1: dating pool. Essentially, specifically, they allowed some males of this 551 00:32:08,320 --> 00:32:11,680 Speaker 1: praying man of species to encounter and court more females 552 00:32:11,720 --> 00:32:15,120 Speaker 1: than others, and then they controlled the risk of predation 553 00:32:15,240 --> 00:32:18,640 Speaker 1: by the females on the males. One thing to notice 554 00:32:18,720 --> 00:32:20,920 Speaker 1: that a male a male can tell when a female 555 00:32:21,000 --> 00:32:24,600 Speaker 1: is hungry, and the hungrier she is, the more cautious 556 00:32:24,640 --> 00:32:28,160 Speaker 1: they are. However, what they found is that if the 557 00:32:28,280 --> 00:32:32,680 Speaker 1: male is sex starved, he will take risks with hungrier females. 558 00:32:33,440 --> 00:32:35,400 Speaker 1: And in the wild, it's worth pointing out, as we 559 00:32:35,400 --> 00:32:37,600 Speaker 1: said earlier, most of the time you're going to be 560 00:32:37,640 --> 00:32:39,920 Speaker 1: on the verge of starvation. Females in the wild are 561 00:32:40,040 --> 00:32:43,920 Speaker 1: usually hungry. So what what did they find? They found 562 00:32:44,000 --> 00:32:48,680 Speaker 1: sexually frustrated males are and those are again sorry anthropomorphine language. 563 00:32:48,880 --> 00:32:52,360 Speaker 1: The males who had had fewer chances to encounter females 564 00:32:52,400 --> 00:32:55,240 Speaker 1: in court them the ones that are sexually frustrated, We're 565 00:32:55,240 --> 00:32:58,600 Speaker 1: willing to take more risks with more dangerous females in 566 00:32:58,720 --> 00:33:01,440 Speaker 1: return for chances to mate. And the males who had 567 00:33:01,520 --> 00:33:03,960 Speaker 1: had more time around females that had been exposed to 568 00:33:04,000 --> 00:33:08,000 Speaker 1: more females, they were more cautious, approached the females more 569 00:33:08,040 --> 00:33:12,760 Speaker 1: slowly and stayed farther away. Um. And the ones who 570 00:33:12,760 --> 00:33:14,960 Speaker 1: had not been exposed to females, they basically just said 571 00:33:15,000 --> 00:33:17,240 Speaker 1: to hell with it and they ran in there. Okay, 572 00:33:17,280 --> 00:33:20,400 Speaker 1: So yeah, it comes down to what kind of risk 573 00:33:20,440 --> 00:33:23,960 Speaker 1: are they willing to take to carry out their genetic mission. Yeah, 574 00:33:24,000 --> 00:33:26,240 Speaker 1: And then there was also a second experiment where the 575 00:33:26,280 --> 00:33:30,080 Speaker 1: researchers tried this with hungry females and well fed females, 576 00:33:30,440 --> 00:33:33,680 Speaker 1: and they found that the hungry females plus sexually frustrated 577 00:33:33,720 --> 00:33:37,520 Speaker 1: males that that combination did in fact lead to cannibalism. 578 00:33:37,640 --> 00:33:40,760 Speaker 1: Uh they said, quote greater risk taking behavior by males 579 00:33:40,800 --> 00:33:43,960 Speaker 1: with low mate encounter rates resulted in high rates of 580 00:33:44,000 --> 00:33:48,000 Speaker 1: sexual cannibalism when these males were paired with hungry females. 581 00:33:48,440 --> 00:33:51,520 Speaker 1: So it essentially paints a picture of how to make 582 00:33:51,720 --> 00:33:56,280 Speaker 1: a male praying mantis suicidal. You take away his access 583 00:33:56,360 --> 00:34:00,080 Speaker 1: to to lady friends. There you go, Okay, but we 584 00:34:00,120 --> 00:34:02,080 Speaker 1: should look, we should get back to some spiders because 585 00:34:02,120 --> 00:34:06,120 Speaker 1: the classic example of sexual cannibalism in the wild is 586 00:34:06,160 --> 00:34:08,399 Speaker 1: going to be the black widow. But but let's let's 587 00:34:08,400 --> 00:34:10,920 Speaker 1: look at a relative of the black widow. That's right, 588 00:34:10,920 --> 00:34:14,120 Speaker 1: We're gonna look at red back spiders, who are relatives, 589 00:34:14,120 --> 00:34:17,080 Speaker 1: and they have males. They're seemingly quite willing to take 590 00:34:17,160 --> 00:34:20,360 Speaker 1: the risk of being cannibalized. It's another one of these 591 00:34:20,400 --> 00:34:23,680 Speaker 1: species where we see some some rather intense uh sexual 592 00:34:23,680 --> 00:34:28,000 Speaker 1: dimorphism here because the uh, the the the females are 593 00:34:28,080 --> 00:34:32,800 Speaker 1: are far larger while the males are tiny. About the 594 00:34:32,840 --> 00:34:35,440 Speaker 1: size of a grain of rice. Females live for up 595 00:34:35,440 --> 00:34:38,080 Speaker 1: to two years, while males generally only make it four 596 00:34:38,120 --> 00:34:42,160 Speaker 1: to eight weeks. Oh man, Yeah, so so that's one example. 597 00:34:42,200 --> 00:34:44,560 Speaker 1: Like we were talking about at the beginning, like we 598 00:34:44,560 --> 00:34:47,480 Speaker 1: we can't help but overlaying our sort of social values 599 00:34:47,520 --> 00:34:49,879 Speaker 1: onto the lives of these insects. But it really does 600 00:34:49,960 --> 00:34:53,520 Speaker 1: look there like the female is what's being valued somehow 601 00:34:53,560 --> 00:34:56,279 Speaker 1: by nature and the males just kind of there to 602 00:34:56,360 --> 00:34:59,440 Speaker 1: provide some sperm and disappear. Yeah, and then you know 603 00:34:59,480 --> 00:35:03,000 Speaker 1: it also comes from our attachment to life, I think too, 604 00:35:03,120 --> 00:35:05,440 Speaker 1: where you say, well, one lives longer, one's got a 605 00:35:05,440 --> 00:35:08,560 Speaker 1: bigger body, one seems to have more of a sensory 606 00:35:08,600 --> 00:35:11,239 Speaker 1: experience of the world, whereas I mean, it really comes 607 00:35:11,280 --> 00:35:14,720 Speaker 1: down to they each have their genetic mission, they both 608 00:35:15,160 --> 00:35:18,439 Speaker 1: carry it out. Ultimately, Hey, you could say the male 609 00:35:18,520 --> 00:35:21,120 Speaker 1: wins because he did it faster, he got to the 610 00:35:21,120 --> 00:35:26,480 Speaker 1: finish line, mission accomplished. Uh, no longer wasting resources. But 611 00:35:26,920 --> 00:35:30,839 Speaker 1: during copulation among the red back spiders, the smaller male 612 00:35:30,920 --> 00:35:35,400 Speaker 1: spider positions itself above the female's jaws. And this apparent 613 00:35:35,520 --> 00:35:37,440 Speaker 1: to male here I am, yeah, here, i am, I'm 614 00:35:37,520 --> 00:35:40,800 Speaker 1: right here, and this apparent male complicity. Complicity and sexual 615 00:35:40,800 --> 00:35:46,160 Speaker 1: cannibalism is favored by sexual selection because cannibalized spiders receive 616 00:35:46,560 --> 00:35:49,759 Speaker 1: a number of a paternity advantages. Oh really, so they're 617 00:35:49,840 --> 00:35:53,160 Speaker 1: they're documented cases here that show that it's better to 618 00:35:53,200 --> 00:35:56,920 Speaker 1: be cannibalized. So it would seem so genetically better, not 619 00:35:57,040 --> 00:35:59,360 Speaker 1: so much for the individual. Yeah, but again then we're 620 00:35:59,360 --> 00:36:03,759 Speaker 1: being we're rejecting conscious experience onto these these guys. So 621 00:36:04,040 --> 00:36:08,520 Speaker 1: cannibalized males copulate longer and they fertilize more eggs than 622 00:36:08,640 --> 00:36:13,560 Speaker 1: those who survive. Okay, so that's one advantage. Another advantage, 623 00:36:13,680 --> 00:36:17,920 Speaker 1: females are more likely to reject subsequent suitors after consuming 624 00:36:18,000 --> 00:36:21,920 Speaker 1: their first mate. Uh. And these results represent to empirical 625 00:36:22,000 --> 00:36:25,959 Speaker 1: evidence for uh, what is sometimes referred to as male 626 00:36:26,480 --> 00:36:30,200 Speaker 1: copulatory suicide as an adapted behavior. And of course, but 627 00:36:30,280 --> 00:36:34,759 Speaker 1: of course that's a highly anthropomorphizing term, so too. Back 628 00:36:34,840 --> 00:36:37,880 Speaker 1: to our analogy that this is again saying, this strangely 629 00:36:38,120 --> 00:36:42,160 Speaker 1: counterintuitive seeming behavior is itself being selected for. It's not 630 00:36:42,320 --> 00:36:45,759 Speaker 1: like a byproduct of something, It is itself the trait 631 00:36:45,960 --> 00:36:49,719 Speaker 1: that's beneficial. Kicking people in the face is good, yes, 632 00:36:50,480 --> 00:36:53,520 Speaker 1: And then there's this uh, they deposit a sperm plug 633 00:36:53,960 --> 00:36:56,840 Speaker 1: and so this is a small part of their copulatory 634 00:36:57,080 --> 00:37:00,600 Speaker 1: organ that stays inside the female uh. And then it 635 00:37:00,719 --> 00:37:04,239 Speaker 1: prevents any future males from successfully fertilizing her eggs, meaning 636 00:37:04,320 --> 00:37:07,880 Speaker 1: that males have to mate with a virgin spider to 637 00:37:08,160 --> 00:37:14,800 Speaker 1: maximize their reproductive success. So competition is tough then for 638 00:37:14,880 --> 00:37:18,480 Speaker 1: the male redback spider for a couple of different reasons here, 639 00:37:18,840 --> 00:37:21,279 Speaker 1: And they only get that one mating opportunity to carry 640 00:37:21,280 --> 00:37:23,759 Speaker 1: it out. That's it. And given the whole sperm plug thing, 641 00:37:23,960 --> 00:37:26,680 Speaker 1: they have to act fast and they also might get eaten, 642 00:37:26,760 --> 00:37:29,440 Speaker 1: so so be it. But they also have to make 643 00:37:29,480 --> 00:37:33,520 Speaker 1: sure that they have enough energy to carry out the deed. Interesting, yeah, 644 00:37:33,960 --> 00:37:36,480 Speaker 1: and this is so they might not they might fail, 645 00:37:36,600 --> 00:37:40,000 Speaker 1: they might be too weary to survive the copulation long 646 00:37:40,080 --> 00:37:43,600 Speaker 1: and or not survive, but to perform the copulation correctly right, 647 00:37:43,680 --> 00:37:45,600 Speaker 1: And this is where we get into I think it's 648 00:37:45,640 --> 00:37:48,080 Speaker 1: helpful to think of the mail and a weaponized sense 649 00:37:48,160 --> 00:37:51,719 Speaker 1: as a he is. He is a warhead, that is 650 00:37:51,920 --> 00:37:54,400 Speaker 1: that has sent on a mission to reach a destination. 651 00:37:54,840 --> 00:37:58,280 Speaker 1: He has to have the appropriate navigational tools and fuel 652 00:37:58,760 --> 00:38:02,160 Speaker 1: to to reach that death donation. But as it is 653 00:38:02,280 --> 00:38:05,600 Speaker 1: with you know, in rocketry, you you don't you don't 654 00:38:05,640 --> 00:38:07,879 Speaker 1: want to supply too much fuel. You want just enough 655 00:38:07,880 --> 00:38:10,320 Speaker 1: fuel to get where you're going, right, And that actually 656 00:38:10,360 --> 00:38:14,080 Speaker 1: plays into the development of the male redback spider. According 657 00:38:14,160 --> 00:38:16,880 Speaker 1: to a two thousand and six University of Toronto study, 658 00:38:17,160 --> 00:38:20,440 Speaker 1: the speed of their development actually depends on the density 659 00:38:20,560 --> 00:38:24,719 Speaker 1: of females in their surroundings. When males can smell females 660 00:38:25,760 --> 00:38:29,760 Speaker 1: in abundance, they develop rapidly, settling for a smaller body 661 00:38:29,840 --> 00:38:35,040 Speaker 1: size and less fat reserves. All also that he can 662 00:38:35,080 --> 00:38:37,920 Speaker 1: get to those virgin females sooner and if there are 663 00:38:38,280 --> 00:38:40,640 Speaker 1: if there are plenty around, he doesn't need the fat 664 00:38:40,719 --> 00:38:43,560 Speaker 1: preserves in order to survive a long search for a mate. 665 00:38:43,640 --> 00:38:47,200 Speaker 1: But likewise, if he can smell uh, you know, he 666 00:38:47,280 --> 00:38:49,560 Speaker 1: doesn't smell any females in the vicinity or they are 667 00:38:49,680 --> 00:38:51,839 Speaker 1: very few, then they're gonna go ahead and develop those 668 00:38:51,960 --> 00:38:55,000 Speaker 1: those fat reserves so that he can actually survive a 669 00:38:55,080 --> 00:39:00,640 Speaker 1: longer trip. Oh wow, So it's sexually strategic storage of energy. Yeah, exactly. 670 00:39:01,000 --> 00:39:02,640 Speaker 1: And if there are a lot of males in the 671 00:39:02,719 --> 00:39:05,880 Speaker 1: area already, they tend to go smaller on size but 672 00:39:06,000 --> 00:39:09,160 Speaker 1: with greater fat stores to sustain them through. And I 673 00:39:09,280 --> 00:39:12,680 Speaker 1: love this the extended courtship rituals in which the male 674 00:39:12,800 --> 00:39:15,880 Speaker 1: has to essentially play music on the female's web, just 675 00:39:16,120 --> 00:39:20,160 Speaker 1: like strumming the chords for up to eight hours at 676 00:39:20,200 --> 00:39:23,200 Speaker 1: a time. What yeah, And if she apparently she doesn't 677 00:39:23,320 --> 00:39:26,960 Speaker 1: like the song he's playing, she doesn't necessarily eat him. 678 00:39:27,000 --> 00:39:29,400 Speaker 1: She may just swat him off the web. We we 679 00:39:29,600 --> 00:39:34,359 Speaker 1: are just we are jumping the anthropomorphism shark here I am. 680 00:39:34,600 --> 00:39:36,759 Speaker 1: I am so sorry to the people who don't want 681 00:39:36,760 --> 00:39:39,320 Speaker 1: to hear the anthropomorphism because we have gone off the deeper. 682 00:39:39,719 --> 00:39:42,360 Speaker 1: How is there any way we could do this topic otherwise? 683 00:39:42,440 --> 00:39:46,680 Speaker 1: For some reason, it just demands this biased, inappropriate language. 684 00:39:47,000 --> 00:39:48,960 Speaker 1: I think the thing is, if you strip away the 685 00:39:49,920 --> 00:39:54,560 Speaker 1: anti anthropomorphism, it ultimately becomes less interesting to talk about, 686 00:39:55,160 --> 00:39:58,439 Speaker 1: less interesting to listen to, and harder to convey because 687 00:39:58,480 --> 00:40:01,319 Speaker 1: instead of saying, he plays there a song on a spiderweb, 688 00:40:01,440 --> 00:40:05,640 Speaker 1: I have to get into a far stuffier um biological 689 00:40:05,800 --> 00:40:09,520 Speaker 1: language about what's actually going on, And ultimately I'm conveying 690 00:40:09,600 --> 00:40:12,120 Speaker 1: the same thing. Like it's either you're easier just to say, hey, 691 00:40:12,680 --> 00:40:18,160 Speaker 1: this is gonna be a little anthropomorphic, so just be aware. Well, 692 00:40:18,200 --> 00:40:20,400 Speaker 1: I didn't mean that as a criticism. I mean I'm 693 00:40:20,440 --> 00:40:24,120 Speaker 1: doing it too. Uh yeah, I mean what what does 694 00:40:24,160 --> 00:40:26,200 Speaker 1: it take though for a spider to become good at 695 00:40:26,239 --> 00:40:29,080 Speaker 1: playing the strings? Does he have to practice? I don't know. 696 00:40:29,160 --> 00:40:32,480 Speaker 1: It's certainly not extensive practice because he really has to 697 00:40:32,600 --> 00:40:35,600 Speaker 1: jump right in there, right. Yeah. So here's one thing 698 00:40:35,640 --> 00:40:38,360 Speaker 1: I was wondering. It seems like in every case we 699 00:40:38,480 --> 00:40:42,200 Speaker 1: look at of sexual cannibalism, it's the female eating the male. 700 00:40:42,360 --> 00:40:44,920 Speaker 1: And this obviously makes sense because the female is the 701 00:40:45,080 --> 00:40:48,560 Speaker 1: egg carrying member of the species. So I mean, it 702 00:40:48,760 --> 00:40:51,160 Speaker 1: just wouldn't make sense for a male to eat a 703 00:40:51,239 --> 00:40:54,719 Speaker 1: female after copulation because that would destroy all chances of 704 00:40:54,920 --> 00:40:57,759 Speaker 1: of reproduction happening from you know, you would eat the 705 00:40:57,840 --> 00:41:01,400 Speaker 1: female and then the fertilized eggs would not survive probably, 706 00:41:02,120 --> 00:41:04,759 Speaker 1: and then what was the point of copulation? That just 707 00:41:04,800 --> 00:41:07,879 Speaker 1: seems like wasted energy resources. But is there any case 708 00:41:07,960 --> 00:41:11,960 Speaker 1: where some version of this could happen? There is? Interestingly enough, 709 00:41:12,040 --> 00:41:15,520 Speaker 1: we do find an example of reverse sexual cannibalism in 710 00:41:15,719 --> 00:41:20,640 Speaker 1: the mi Carria sociabilist spiders. It essentially boils down to 711 00:41:20,719 --> 00:41:23,920 Speaker 1: a form of mate male mate selection, much like that 712 00:41:24,000 --> 00:41:28,239 Speaker 1: employed by various female cannibals. So I see that if 713 00:41:28,280 --> 00:41:30,719 Speaker 1: it depends kind of when you when you discuss like 714 00:41:30,840 --> 00:41:34,960 Speaker 1: how unrealistic would male sexual cannibalism be, It kind of 715 00:41:35,080 --> 00:41:37,360 Speaker 1: depends on which theory you're throwing at it. So if 716 00:41:37,400 --> 00:41:40,399 Speaker 1: you're going with a mate selection, yeah, you could see 717 00:41:40,440 --> 00:41:43,919 Speaker 1: where a male could say, Nope, don't want to breed 718 00:41:44,000 --> 00:41:47,000 Speaker 1: with that that female. That breeding with that female is 719 00:41:47,120 --> 00:41:50,360 Speaker 1: not going to give me optimal results on my genetic 720 00:41:50,440 --> 00:41:54,320 Speaker 1: mission here, better off that I eat her and uh So. 721 00:41:54,480 --> 00:41:58,040 Speaker 1: In two thousand thirteen, a team of researchers from Messeric 722 00:41:58,200 --> 00:42:01,440 Speaker 1: University in the Czech Republic found that young males from 723 00:42:01,520 --> 00:42:06,080 Speaker 1: the summer generation of these particular spiders were the were 724 00:42:06,120 --> 00:42:09,359 Speaker 1: the most likely cannibals here, and they tended to cannibalize 725 00:42:09,480 --> 00:42:14,960 Speaker 1: older females of the previous spring generation. So male size 726 00:42:15,000 --> 00:42:17,800 Speaker 1: and aggressions seem to play a role in all of this, 727 00:42:18,480 --> 00:42:23,120 Speaker 1: uh and female virginity or lack thereof did not. So 728 00:42:23,880 --> 00:42:25,560 Speaker 1: this is another case where we're also getting a little 729 00:42:25,560 --> 00:42:29,280 Speaker 1: bit of the aggression spillover model in there as well. Okay, 730 00:42:30,120 --> 00:42:32,319 Speaker 1: but for the most part, it seems to come down 731 00:42:32,360 --> 00:42:34,799 Speaker 1: to mate selection. Yeah, so it seems like we've seen 732 00:42:34,800 --> 00:42:37,800 Speaker 1: a couple of scenarios where those two hypotheses are not 733 00:42:37,960 --> 00:42:41,239 Speaker 1: necessarily in conflict. They can sort of work together, right. 734 00:42:41,640 --> 00:42:43,640 Speaker 1: You know. One of the things that this is kind 735 00:42:43,640 --> 00:42:45,000 Speaker 1: of a side note, but one of the things that's 736 00:42:45,040 --> 00:42:47,840 Speaker 1: been interesting to me in looking at this research is 737 00:42:47,880 --> 00:42:51,839 Speaker 1: the different examples of uh I guess males that can 738 00:42:51,960 --> 00:42:55,480 Speaker 1: continue the mating process after they have been partially consumed 739 00:42:55,560 --> 00:42:59,800 Speaker 1: or dismembered. Particularly you see this with with some of 740 00:42:59,840 --> 00:43:03,040 Speaker 1: the the mantis species out there, right, some mantids, the 741 00:43:03,120 --> 00:43:06,120 Speaker 1: males can continue to mate after their their heads bitten off, 742 00:43:07,000 --> 00:43:08,520 Speaker 1: And I think this is the case with some of 743 00:43:08,600 --> 00:43:12,000 Speaker 1: the spiders too, right, they can like they can inject 744 00:43:12,200 --> 00:43:15,600 Speaker 1: a sexual organ into the female and then they can 745 00:43:15,680 --> 00:43:19,319 Speaker 1: basically be eaten while those individual organs are still doing 746 00:43:19,360 --> 00:43:21,839 Speaker 1: their work. Yeah. I mean, we already discussed in one 747 00:43:21,920 --> 00:43:25,240 Speaker 1: case where the female made it longer with the males 748 00:43:25,280 --> 00:43:28,120 Speaker 1: who are cannibalized. So it's kind of like, if I'm 749 00:43:28,160 --> 00:43:31,719 Speaker 1: cool again to anthropomorphize, if I'm cool with having my 750 00:43:31,840 --> 00:43:34,520 Speaker 1: head eaten off, I actually am going to get in 751 00:43:34,600 --> 00:43:38,520 Speaker 1: there longer doing the thing that I am designed to do. 752 00:43:40,880 --> 00:43:43,719 Speaker 1: So it makes sense, right, it makes so much sense. 753 00:43:45,719 --> 00:43:47,279 Speaker 1: It's like she's gonna eat me, but I'm gonna be 754 00:43:47,360 --> 00:43:58,360 Speaker 1: there twice as long. It all evens out. Now, there 755 00:43:58,480 --> 00:44:02,080 Speaker 1: was another interesting finding that I wanted to talk about briefly, 756 00:44:02,800 --> 00:44:08,800 Speaker 1: which was about sexual deception in a cannibalistic mating system. Yeah. So, 757 00:44:09,080 --> 00:44:12,520 Speaker 1: so there was a paper published in called sexual Deception 758 00:44:12,600 --> 00:44:16,640 Speaker 1: in a Cannibalistic Mating System testing the film Fatale hypothesis. 759 00:44:16,719 --> 00:44:20,320 Speaker 1: And this was by the scientist Catherine L. Berry in 760 00:44:21,000 --> 00:44:24,880 Speaker 1: Biological Sciences, Proceedings of the Royal Society b And this 761 00:44:25,080 --> 00:44:29,319 Speaker 1: was a study of the female false garden mantis. Now, 762 00:44:29,560 --> 00:44:34,200 Speaker 1: what the false garden mantis does is she has pheromones 763 00:44:34,400 --> 00:44:38,640 Speaker 1: that are taken as good faith signals of her fecundity, 764 00:44:38,800 --> 00:44:42,520 Speaker 1: of of how likely she is to produce numbers of 765 00:44:42,600 --> 00:44:46,479 Speaker 1: healthy offspring. So mantis is that are in better health, 766 00:44:46,520 --> 00:44:49,799 Speaker 1: they're in better shape, they're more well fed. They give 767 00:44:49,840 --> 00:44:53,480 Speaker 1: off pheromones that advertise to males like, hey, I'm good 768 00:44:53,520 --> 00:44:56,000 Speaker 1: to go. We we are going to have lots of 769 00:44:56,040 --> 00:45:00,080 Speaker 1: beautiful children together if you come mate with me. What 770 00:45:00,400 --> 00:45:03,520 Speaker 1: also within this mantis species, there is some rate of 771 00:45:03,640 --> 00:45:06,719 Speaker 1: sexual cannibalism where the female will eat the male UH 772 00:45:07,400 --> 00:45:11,680 Speaker 1: after or during copulation. So this study was supposed to 773 00:45:11,920 --> 00:45:18,000 Speaker 1: examine UH whether or not the females could lie using 774 00:45:18,120 --> 00:45:22,239 Speaker 1: pheromones about how likely they were when what and how 775 00:45:22,320 --> 00:45:25,080 Speaker 1: good health they were you know UH to to the 776 00:45:25,200 --> 00:45:28,200 Speaker 1: males who were coming up to them. So the females 777 00:45:28,239 --> 00:45:33,080 Speaker 1: were given different feeding regimens. Essentially some of them got 778 00:45:33,640 --> 00:45:37,680 Speaker 1: very good nutrition, others got medium nutrition, some got poor nutrition, 779 00:45:37,760 --> 00:45:41,520 Speaker 1: and some got very poor nutrition. And then males were 780 00:45:41,600 --> 00:45:44,799 Speaker 1: allowed to UH. They were they were given the opportunity 781 00:45:45,160 --> 00:45:48,160 Speaker 1: to sort of approach a female that they couldn't see, 782 00:45:48,280 --> 00:45:51,160 Speaker 1: they were visually obscured in the terms of the study 783 00:45:51,719 --> 00:45:54,560 Speaker 1: and UH and so they were just operating off of 784 00:45:54,680 --> 00:45:57,239 Speaker 1: these pheromones that were put out by the females. And 785 00:45:57,320 --> 00:46:00,200 Speaker 1: what the study found is that for most of these 786 00:46:00,280 --> 00:46:03,759 Speaker 1: female mantis is the rate at which the males would 787 00:46:03,760 --> 00:46:06,839 Speaker 1: approach them seemed to be indicating there was good faith 788 00:46:06,920 --> 00:46:10,040 Speaker 1: communication with the pheromones. So males were most likely to 789 00:46:10,120 --> 00:46:12,719 Speaker 1: approach the good the you know, the ones who had 790 00:46:12,760 --> 00:46:15,000 Speaker 1: been on a good feeding schedule, and then a little 791 00:46:15,120 --> 00:46:18,799 Speaker 1: less likely to approach the ones on the medium UH 792 00:46:19,120 --> 00:46:22,080 Speaker 1: feeding schedule. So so there was a pretty much correct 793 00:46:22,239 --> 00:46:26,719 Speaker 1: advertisement system there except for one case, and that one 794 00:46:26,800 --> 00:46:30,000 Speaker 1: case that did not fit were the females who had 795 00:46:30,040 --> 00:46:33,399 Speaker 1: had the very poor feeding schedule, the ones who got 796 00:46:33,520 --> 00:46:37,719 Speaker 1: fed the worst, and those actually attracted more males than 797 00:46:37,880 --> 00:46:42,040 Speaker 1: any of the other female feeding regimens, even though that 798 00:46:42,160 --> 00:46:44,640 Speaker 1: meant the females were in the least good health and 799 00:46:44,719 --> 00:46:47,759 Speaker 1: they were the least likely to produce good numbers of 800 00:46:47,920 --> 00:46:50,840 Speaker 1: healthy offspring, but they were the most in need of 801 00:46:50,920 --> 00:46:54,160 Speaker 1: a good cannibal meal, right exactly. And so a previous 802 00:46:54,200 --> 00:46:56,960 Speaker 1: study had found that these females were more likely to 803 00:46:57,040 --> 00:46:59,560 Speaker 1: cannibalize males the ones who had had the least to eat. 804 00:46:59,640 --> 00:47:02,160 Speaker 1: So the greer the female is, the more likely she 805 00:47:02,320 --> 00:47:05,920 Speaker 1: is to eat her mate. Now, studies necessarily or have 806 00:47:06,120 --> 00:47:09,400 Speaker 1: not necessarily found the same thing about other insects and ragnets. 807 00:47:09,440 --> 00:47:12,400 Speaker 1: But in this one particular species, it seems that despite 808 00:47:12,440 --> 00:47:16,200 Speaker 1: the fact that there's basically a correct or good faith 809 00:47:16,239 --> 00:47:20,919 Speaker 1: pheromone signaling system, uh, there are some cases in which 810 00:47:21,040 --> 00:47:26,320 Speaker 1: individuals will violate it in order to eat somebody interact. 811 00:47:27,360 --> 00:47:30,640 Speaker 1: So we get we get deception on top of everything 812 00:47:30,680 --> 00:47:32,960 Speaker 1: else that we're dealing with here. Now there's one more 813 00:47:33,040 --> 00:47:34,759 Speaker 1: paper I'd like to talk about that I thought was 814 00:47:34,800 --> 00:47:38,879 Speaker 1: pretty interesting. It's not directly addressing sexual cannibalism as its 815 00:47:38,960 --> 00:47:41,719 Speaker 1: main focus, but it had some cool observations about it. 816 00:47:42,280 --> 00:47:46,600 Speaker 1: And it's a paper called conditional monogamy Female Quality predicts 817 00:47:46,680 --> 00:47:50,000 Speaker 1: Male Faithfulness and it was published in Frontiers in Zoology 818 00:47:50,080 --> 00:47:54,440 Speaker 1: in So the premise of this paper is that males 819 00:47:54,560 --> 00:47:58,359 Speaker 1: from lots of animal species display polygony, you know, having 820 00:47:58,560 --> 00:48:01,960 Speaker 1: lots of wives, mating with more than one female, usually 821 00:48:02,040 --> 00:48:05,600 Speaker 1: as many females as he can. But some animal species 822 00:48:05,719 --> 00:48:09,000 Speaker 1: display I guess the inverse of that monogamy, wherein the 823 00:48:09,120 --> 00:48:13,359 Speaker 1: male only mates with one female in his entire lifetime. Now, 824 00:48:13,520 --> 00:48:15,719 Speaker 1: this might be for multiple reasons. The male might be 825 00:48:16,000 --> 00:48:20,279 Speaker 1: involved in uh for for example, parent parental duties maybe, 826 00:48:21,480 --> 00:48:23,960 Speaker 1: But there there are some species where that doesn't really 827 00:48:24,000 --> 00:48:26,200 Speaker 1: seem to be the case. Yet there is still just 828 00:48:26,600 --> 00:48:30,240 Speaker 1: mating with one female in the lifetime. And this would include, 829 00:48:30,520 --> 00:48:34,360 Speaker 1: especially to interest to our interests, several species of spiders. 830 00:48:34,920 --> 00:48:37,839 Speaker 1: Now that this is a quote from the paper, monogamy 831 00:48:37,960 --> 00:48:43,280 Speaker 1: is associated with curious adaptations like lifelong associations between males 832 00:48:43,320 --> 00:48:45,880 Speaker 1: and females. I like how that's a curious adaptation, but 833 00:48:46,000 --> 00:48:53,040 Speaker 1: also extreme sexual size, dimorphism, genital damage, and sexual cannibalism. Okay, 834 00:48:53,120 --> 00:48:55,759 Speaker 1: so that just lays out the obvious that sometimes you 835 00:48:55,840 --> 00:48:58,239 Speaker 1: meet that special person and that's the only person you 836 00:48:58,320 --> 00:48:59,520 Speaker 1: want to be with for the rest of your life. 837 00:48:59,600 --> 00:49:02,000 Speaker 1: Other times times they kill you and eat you or 838 00:49:02,080 --> 00:49:04,920 Speaker 1: damage your genitals. Yeah. So, uh so, Now, if you 839 00:49:05,000 --> 00:49:07,880 Speaker 1: look at a male spider sex organs, one thing you 840 00:49:07,960 --> 00:49:10,680 Speaker 1: might see is that the male spider has these two 841 00:49:10,760 --> 00:49:14,520 Speaker 1: copulatory organs called the pet a palps that are used 842 00:49:14,560 --> 00:49:18,120 Speaker 1: for copulation. These are sort of like miniature arms coming 843 00:49:18,160 --> 00:49:21,680 Speaker 1: out of the spider's head. Also, it is likely that 844 00:49:21,800 --> 00:49:25,320 Speaker 1: these organs will be damaged in mating, So essentially, the 845 00:49:25,440 --> 00:49:30,440 Speaker 1: male spider has two detachable penises available for his mating budget. 846 00:49:31,200 --> 00:49:34,040 Speaker 1: And the females, on the other hand, can mate multiple times. 847 00:49:34,640 --> 00:49:38,440 Speaker 1: So the female spider has a pair of incimination ducts. 848 00:49:38,600 --> 00:49:41,120 Speaker 1: These are her her mating openings, and these can be 849 00:49:41,239 --> 00:49:45,239 Speaker 1: in a sense plugged by a broken off piece of 850 00:49:45,400 --> 00:49:49,520 Speaker 1: male spider copulatory organs. That makes sense, so he can 851 00:49:49,640 --> 00:49:52,239 Speaker 1: break off part of his pet a palp in her 852 00:49:52,920 --> 00:49:57,560 Speaker 1: incimination duct to prevent other male rivals from successfully coming 853 00:49:57,600 --> 00:50:00,760 Speaker 1: along and mating with that same female, like a stabbing 854 00:50:00,800 --> 00:50:04,280 Speaker 1: in a Cormack McCarthy novel where they snapped the blade 855 00:50:04,320 --> 00:50:07,040 Speaker 1: off in the wound. Yeah. Yeah, it sounds pretty violent 856 00:50:07,239 --> 00:50:09,640 Speaker 1: in our terms, but but I guess this is how 857 00:50:09,680 --> 00:50:12,719 Speaker 1: the spiders work. We we shall not judge now. The 858 00:50:12,760 --> 00:50:15,320 Speaker 1: study in particular is focused on the orb web spider 859 00:50:15,520 --> 00:50:18,959 Speaker 1: known as the wasp spider or our guy ape bruiniqui, 860 00:50:19,520 --> 00:50:22,879 Speaker 1: and as a few mating stats from previous research show, 861 00:50:22,960 --> 00:50:26,120 Speaker 1: one is that in the laboratory, females are quote highly 862 00:50:26,239 --> 00:50:30,080 Speaker 1: cannibalistic and eight percent of males are killed during their 863 00:50:30,080 --> 00:50:33,279 Speaker 1: first copulation. That's a lot pretty high. Yeah yeah. They 864 00:50:33,320 --> 00:50:37,680 Speaker 1: also say genital damage is very common in a bruin bruiniqui, 865 00:50:38,000 --> 00:50:41,359 Speaker 1: and it occurs in eighty five percent of copulations into 866 00:50:41,560 --> 00:50:44,640 Speaker 1: unused genital openings, So there's a really good chance that 867 00:50:44,920 --> 00:50:48,120 Speaker 1: you get your sexual organ broken off inside the female. 868 00:50:49,040 --> 00:50:51,000 Speaker 1: And then on top of that, they say the broken 869 00:50:51,040 --> 00:50:54,319 Speaker 1: off pieces remain in the female insemination duc to nine 870 00:50:54,880 --> 00:50:57,279 Speaker 1: percent of these cases, so that these things, when they 871 00:50:57,320 --> 00:51:01,120 Speaker 1: get broken off, are highly effective in plugging the hole 872 00:51:01,280 --> 00:51:03,840 Speaker 1: so that other males can't come along and mate with 873 00:51:03,920 --> 00:51:08,400 Speaker 1: the same female. So that's one positive reason for detaching 874 00:51:08,680 --> 00:51:14,680 Speaker 1: one's penises. Yeah, among others, I assume h No, I 875 00:51:14,840 --> 00:51:19,239 Speaker 1: bet that's the only one. But anyway, so, since the 876 00:51:19,320 --> 00:51:22,000 Speaker 1: male sex organs tend to get broken off, he has 877 00:51:22,040 --> 00:51:24,279 Speaker 1: a choice. He has two of these things, and he 878 00:51:24,360 --> 00:51:28,560 Speaker 1: can spend them both on the same female. This would 879 00:51:28,560 --> 00:51:31,800 Speaker 1: be the case of monogamy, mating with only one female 880 00:51:31,840 --> 00:51:33,960 Speaker 1: in his lifetime, or he can try to mate with 881 00:51:34,040 --> 00:51:36,960 Speaker 1: two different females in his lifetime. Okay, so we see 882 00:51:37,040 --> 00:51:41,080 Speaker 1: us a form of mate selection here that he can 883 00:51:41,239 --> 00:51:43,880 Speaker 1: decide if this is definitely the one so much so 884 00:51:43,960 --> 00:51:46,080 Speaker 1: that he wants to double down on this mate selection, 885 00:51:46,360 --> 00:51:49,160 Speaker 1: or if he wants to save one keep one in 886 00:51:49,239 --> 00:51:51,919 Speaker 1: the chamber for labor later use. Right. It's like if 887 00:51:52,000 --> 00:51:54,239 Speaker 1: you're you know, you know, you're you're playing Roulette and 888 00:51:54,280 --> 00:51:55,960 Speaker 1: you have two chips. Do you put them on two 889 00:51:56,040 --> 00:51:57,840 Speaker 1: different numbers? Or do you put them both on the 890 00:51:57,920 --> 00:52:01,120 Speaker 1: same number. I'll in on black wa Right. So, the 891 00:52:01,200 --> 00:52:04,640 Speaker 1: researchers tested interactions between these spiders and they found lots 892 00:52:04,680 --> 00:52:07,719 Speaker 1: of interesting correlations. For example, the size of the male 893 00:52:07,960 --> 00:52:10,840 Speaker 1: did not seem to have any impact on the mating strategy, 894 00:52:10,920 --> 00:52:14,359 Speaker 1: but the size of the female did So when when 895 00:52:14,400 --> 00:52:17,200 Speaker 1: a male encountered a female for the first time, the 896 00:52:17,360 --> 00:52:20,440 Speaker 1: bigger the female, the more likely the male was to 897 00:52:20,600 --> 00:52:23,560 Speaker 1: use his entire mating budget on her to give her 898 00:52:23,760 --> 00:52:27,360 Speaker 1: both of his sex organs. Also, when a male mated 899 00:52:27,440 --> 00:52:29,800 Speaker 1: with two different females, when he decided to spread it 900 00:52:29,880 --> 00:52:34,160 Speaker 1: over two different two different numbers on roulette, the second 901 00:52:34,280 --> 00:52:37,120 Speaker 1: female he broke off a sex organ with tended to 902 00:52:37,280 --> 00:52:39,759 Speaker 1: be heavier than the first, so he would tend to 903 00:52:39,920 --> 00:52:43,880 Speaker 1: trade up for a larger female. The larger the female 904 00:52:44,160 --> 00:52:46,560 Speaker 1: usually the more fecand well like a lot of what 905 00:52:46,640 --> 00:52:48,759 Speaker 1: we've discussed here in this episode, and that that makes 906 00:52:48,960 --> 00:52:52,680 Speaker 1: perfect economic sense of course. Now a few other interesting 907 00:52:52,760 --> 00:52:54,560 Speaker 1: things they observed. One of them was that the rate 908 00:52:54,640 --> 00:52:57,640 Speaker 1: of sexual cannibalism they saw in their study was much 909 00:52:57,760 --> 00:53:00,960 Speaker 1: lower than what had been previously reported that number we 910 00:53:01,080 --> 00:53:04,800 Speaker 1: cited earlier. They found that the frequency of cannibalism on 911 00:53:04,920 --> 00:53:08,120 Speaker 1: the first copulation, so the first time male and female 912 00:53:08,160 --> 00:53:12,479 Speaker 1: meet up, was thirty one point four percent. So that's 913 00:53:12,600 --> 00:53:15,839 Speaker 1: lower than than previous studies. But there was also one 914 00:53:15,880 --> 00:53:18,640 Speaker 1: really funny complication of how this worked out. In the 915 00:53:18,760 --> 00:53:23,400 Speaker 1: lab they write, quote, the monogamous males either copulated once 916 00:53:23,880 --> 00:53:25,560 Speaker 1: M one, and this is what they called the group 917 00:53:25,680 --> 00:53:30,600 Speaker 1: M one, which are males cannibalized after a single copulation 918 00:53:31,200 --> 00:53:34,600 Speaker 1: or twice with the same female. In the M one group, 919 00:53:34,680 --> 00:53:37,320 Speaker 1: it cannot be decided whether males would have followed a 920 00:53:37,600 --> 00:53:41,680 Speaker 1: bigginess or monogamous tactic if only they had survived their 921 00:53:41,719 --> 00:53:46,360 Speaker 1: first copulation. So sometimes the male he gets one broken 922 00:53:46,400 --> 00:53:49,279 Speaker 1: off sex organ into the female, but then she eats 923 00:53:49,360 --> 00:53:51,800 Speaker 1: him and you can't tell whether he was planning on 924 00:53:51,960 --> 00:53:55,600 Speaker 1: using both on her or moving on. That's right, because 925 00:53:55,680 --> 00:54:00,960 Speaker 1: she has enacted her a mating choice exactly he can exercise. Yeah, 926 00:54:01,040 --> 00:54:03,560 Speaker 1: And related to that is that one thing they noticed 927 00:54:03,840 --> 00:54:05,600 Speaker 1: was I think this goes along with some of the 928 00:54:05,680 --> 00:54:08,120 Speaker 1: other stuff we've read. How long a male mate it 929 00:54:08,239 --> 00:54:11,960 Speaker 1: during his first copulation was directly positively correlated to the 930 00:54:12,040 --> 00:54:15,040 Speaker 1: rate of sexual cannibalism. So the longer he sticks around, 931 00:54:15,160 --> 00:54:18,320 Speaker 1: the more time he spends locking down his copulation with 932 00:54:18,440 --> 00:54:21,040 Speaker 1: this one female, the higher the chance that he gets 933 00:54:21,120 --> 00:54:23,960 Speaker 1: slain and devoured. All right, now, I want to read 934 00:54:24,040 --> 00:54:27,200 Speaker 1: one more long ish quote from their discussion section because 935 00:54:27,200 --> 00:54:29,480 Speaker 1: I thought it was really interesting related to what we've 936 00:54:29,520 --> 00:54:32,759 Speaker 1: been talking about today. They say, quote some of the 937 00:54:32,880 --> 00:54:37,360 Speaker 1: monogamous males were cannibalized after their first copulation, while others 938 00:54:37,520 --> 00:54:40,600 Speaker 1: used both of their mating options with the same female. 939 00:54:41,160 --> 00:54:44,080 Speaker 1: While the latter can be interpreted as a clear cut 940 00:54:44,280 --> 00:54:47,440 Speaker 1: male decision, So if the male uses both on the 941 00:54:47,520 --> 00:54:50,200 Speaker 1: female and then gets eaten, sort of makes sense for 942 00:54:50,320 --> 00:54:54,239 Speaker 1: him to get eaten, right, um uh, they picked back up. 943 00:54:54,480 --> 00:54:58,320 Speaker 1: Interpreting the decisions of single mated males is more difficult. 944 00:54:58,800 --> 00:55:01,320 Speaker 1: At least, some of these males may have been forced 945 00:55:01,400 --> 00:55:05,240 Speaker 1: into monogamy by aggressive females, while others may have chosen 946 00:55:05,320 --> 00:55:08,920 Speaker 1: to sacrifice themselves to their mating partner already during the 947 00:55:09,000 --> 00:55:13,319 Speaker 1: first copulation. Whether a male falls victim to sexual cannibalism 948 00:55:13,480 --> 00:55:17,040 Speaker 1: during the first copulation is a direct function of its duration. 949 00:55:17,480 --> 00:55:22,359 Speaker 1: Any copulation longer than ten seconds, remember that number will 950 00:55:22,719 --> 00:55:25,799 Speaker 1: most likely end with the death of the males. Well, 951 00:55:25,880 --> 00:55:29,320 Speaker 1: males that jump off before ten seconds have a relatively 952 00:55:29,440 --> 00:55:33,920 Speaker 1: high chance of surviving. Indeed, copulation durations of single mated 953 00:55:34,000 --> 00:55:37,000 Speaker 1: males show a high variance, which suggests that some of 954 00:55:37,120 --> 00:55:40,720 Speaker 1: them chose to copulate for longer in spite of sexual 955 00:55:40,840 --> 00:55:45,000 Speaker 1: cannibalism being the likely consequence, while others attempted to escape 956 00:55:45,360 --> 00:55:49,759 Speaker 1: but failed. So I don't know. I feel like that 957 00:55:49,840 --> 00:55:52,840 Speaker 1: sort of drives home that when you're speaking about evolution, 958 00:55:52,880 --> 00:55:55,320 Speaker 1: it's worth remembering that your body is sort of of 959 00:55:55,480 --> 00:55:58,000 Speaker 1: little use to your genes once you've lost all of 960 00:55:58,080 --> 00:56:01,759 Speaker 1: your reproductive potential. Us, the male individual here is is 961 00:56:01,840 --> 00:56:05,319 Speaker 1: a delivery system for the genetic material. But anyway, if 962 00:56:05,360 --> 00:56:08,719 Speaker 1: you want to read that study, it's again conditional monogamy. 963 00:56:08,800 --> 00:56:12,480 Speaker 1: Female quality predicts male faithfulness is pretty interesting and had 964 00:56:12,520 --> 00:56:15,719 Speaker 1: some other observations too. All right, so there you have it. Uh, 965 00:56:16,400 --> 00:56:20,320 Speaker 1: we've we've discussed sexual cannibalism, some of the theories regarding 966 00:56:20,880 --> 00:56:24,719 Speaker 1: uh it's evolutionary development or a handful of species why 967 00:56:24,800 --> 00:56:26,920 Speaker 1: it seems like it might not make sense, but but 968 00:56:27,320 --> 00:56:30,040 Speaker 1: it probably does. And of course we've engaged in a 969 00:56:30,080 --> 00:56:33,080 Speaker 1: fair amount of anthromomorphism. But still I felt like I 970 00:56:33,160 --> 00:56:36,400 Speaker 1: was holding back in some of so was I. Now, 971 00:56:36,480 --> 00:56:39,080 Speaker 1: if you're a professional researcher in this field, don't take 972 00:56:39,120 --> 00:56:42,839 Speaker 1: a page from us, Try to do do the right thing. 973 00:56:43,000 --> 00:56:45,720 Speaker 1: Be boring, but be accurate. I think, like an insect, 974 00:56:46,160 --> 00:56:49,279 Speaker 1: whenever possible. All right, In the meantime, if you want 975 00:56:49,280 --> 00:56:51,120 Speaker 1: to check out more episodes of Stuff to Blow Your Mind. 976 00:56:51,200 --> 00:56:54,360 Speaker 1: Head on over to our website that's the mothership, stuff 977 00:56:54,360 --> 00:56:56,120 Speaker 1: to Blow your Mind dot com, where you'll find all 978 00:56:56,160 --> 00:56:59,040 Speaker 1: the podcast episodes, videos, blog post links out to our 979 00:56:59,080 --> 00:57:01,839 Speaker 1: social media accounts such as Facebook and Twitter. We are 980 00:57:01,840 --> 00:57:03,800 Speaker 1: blow the Mind on both of those. We are Stuff 981 00:57:03,840 --> 00:57:05,960 Speaker 1: to Blow your Mind on Tumbler And if you want 982 00:57:06,000 --> 00:57:08,080 Speaker 1: to get in touch with us with feedback about this 983 00:57:08,200 --> 00:57:11,680 Speaker 1: episode or any interesting facts you've ever learned about sexual cannibalism, 984 00:57:11,760 --> 00:57:14,440 Speaker 1: you can email us at blow the Mind at how 985 00:57:14,520 --> 00:57:26,160 Speaker 1: stuff works dot com for more on this and thousands 986 00:57:26,200 --> 00:57:28,560 Speaker 1: of other topics. Is it how stuff works dot com 987 00:57:34,640 --> 00:57:36,400 Speaker 1: bla